The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.
Highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning. Many are used as antineoplastic agents, but most are very toxic, with carcinogenic, mutagenic, teratogenic, and immunosuppressant actions. They have also been used as components in poison gases.
A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.
An alkylating agent in cancer therapy that may also act as a mutagen by interfering with and causing damage to DNA.
A group of alkylating agents derived from mustard gas, with the sulfur replaced by nitrogen. They were formerly used as toxicants and vesicants, but now function as antineoplastic agents. These compounds are also powerful mutagens, teratogens, immunosuppressants, and carcinogens.
The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
An alkylating sulfhydryl reagent. Its actions are similar to those of iodoacetate.
A sulfhydryl reagent that is widely used in experimental biochemical studies.
Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.
A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
A nitrosoguanidine derivative with potent mutagenic and carcinogenic properties.
An enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moieties of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Nitrogen mustard derivative of URACIL. It is a alkylating antineoplastic agent that is used in lymphatic malignancies, and causes mainly gastrointestinal and bone marrow damage.
Nitrogen mustard analog of quinacrine used primarily as a stain in the studies of chromosomes and chromatin. Fluoresces by reaction with nucleic acids in chromosomes.
Compounds containing the -SH radical.
Oligopeptide antibiotics from Streptomyces distallicus. Their binding to DNA inhibits synthesis of nucleic acids.
An antibiotic complex produced by Streptomyces kitasatoensis. The complex consists of a mixture of at least eight biologically active components, A1 and A3 to A9. Leucomycins have both antibacterial and antimycoplasmal activities.
The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.
Polymers where the main polymer chain comprises recurring amide groups. These compounds are generally formed from combinations of diamines, diacids, and amino acids and yield fibers, sheeting, or extruded forms used in textiles, gels, filters, sutures, contact lenses, and other biomaterials.
A biologic alkylating agent that exerts its cytotoxic effects by forming DNA ADDUCTS and DNA interstrand crosslinks, thereby inhibiting rapidly proliferating cells. The hydrochloride is an antineoplastic agent used to treat HODGKIN DISEASE and LYMPHOMA.
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.
Hydrazine substituted by one methyl group.
Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.
Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Saturated azacyclopropane compounds. They include compounds with substitutions on CARBON or NITROGEN atoms.
A family of DNA repair enzymes that recognize damaged nucleotide bases and remove them by hydrolyzing the N-glycosidic bond that attaches them to the sugar backbone of the DNA molecule. The process called BASE EXCISION REPAIR can be completed by a DNA-(APURINIC OR APYRIMIDINIC SITE) LYASE which excises the remaining RIBOSE sugar from the DNA.
The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.
Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.
A pyrano-acridone alkaloid found in RUTACEAE plants.
A derivative of ACETIC ACID that contains one IODINE atom attached to its methyl group.
Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The rate dynamics in chemical or physical systems.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.
A class of drugs that differs from other alkylating agents used clinically in that they are monofunctional and thus unable to cross-link cellular macromolecules. Among their common properties are a requirement for metabolic activation to intermediates with antitumor efficacy and the presence in their chemical structures of N-methyl groups, that after metabolism, can covalently modify cellular DNA. The precise mechanisms by which each of these drugs acts to kill tumor cells are not completely understood. (From AMA, Drug Evaluations Annual, 1994, p2026)
Organic salts or esters of methanesulfonic acid.
Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Organic esters of sulfuric acid.
A nitrosamine derivative with alkylating, carcinogenic, and mutagenic properties. It causes serious liver damage and is a hepatocarcinogen in rodents.
A class of compounds that contain a -NH2 and a -NO radical. Many members of this group have carcinogenic and mutagenic properties.
Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)
An antineoplastic agent with alkylating properties. It also acts as a mutagen by damaging DNA and is used experimentally for that effect.

Effect of hepatocarcinogens on the binding of glucocorticoid-receptor complex in rat liver nuclei. (1/1546)

The effects of a number of carcinogens and hepatotoxins on the binding kinetics of the interactions of glucocorticoidcytosol receptor complex with nuclear acceptor sites in rat liver were investigated. Both the apparent sites in rat liver were investigated. Both the apparent concentration of nuclear binding sites and the Kd were significantly diminished following treatment of rats with sublethal doses of the carcinogens aflatoxin B1, diethylnitrosamine, dimethylnitrosamine, thioacetamide, 3'-methyl-4-dimethylaminoazobenzene, 4-dimethylaminoazobenzene, and 3-methylcholanthrene. Treatment with actinomycin D resulted in a slight reduction in the apparent concentration of nuclear acceptor sites but had no effect on the nuclear binding Kd. The hepatotoxic but noncarcinogenic analgesic, acetaminophen, as well as the weakly toxic aflatoxin B1 cognate, aflatoxin B2, were without effect on the kinetics or binding capacity of glucocorticoid-nuclear acceptor site interaction. These experiments suggest that chemically induced alteration of functional glucocorticoid binding sites on chromatin may be involved in the biochemical effects produced in liver by carcinogens of several chemical types. This experimental model may provide a useful approach for further elucidation of early events in carcinogenesis.  (+info)

Effect of sex difference on the in vitro and in vivo metabolism of aflatoxin B1 by the rat. (2/1546)

Hepatic microsome-catalyzed metabolism of aflatoxin B1 (AFB1) to aflatoxin M1 and aflatoxin Q1 and the "metabolic activation" of AFB1 to DNA-alylating metabolite(s) were studied in normal male and female Sprague-Dawley rats, in gonadectomized animals, and in castrated males and normal females treated with testosterone. Microsomes from male animals formed 2 to 5 times more aflatoxin M1, aflatoxin Q1, and DNA-alkylating metabolite(s) than those from females. Castration reduced the metabolism of AFB1 by the microsomes from males by about 50%, whereas ovariectomy had no significant effect on AFB1 metabolism by the microsomes from females. Testosterone treatment (4 mg/rat, 3 times/week for about 6 weeks) of castrated immature males and immature females enhanced the metabolism of AFB1 by their microsomes. A sex difference in the metabolism of AFB1 by liver microsomes was also seen in other strains of rats tested: Wistar, Long-Evans, and Fischer. The activity of kidney microsomes for metabolic activation was 1 to 4% that of the liver activity and was generally lower in microsomes from male rats as compared to those from female rats of Sprague-Dawley, Wistar, and Long-Evans strains. The in vitro results obtained with hepatic microsomes correlated well with the in vivo metabolism of AFB1, in that more AFB1 became bound in vivo to hepatic DNA isolated from male rats and from a female rat treated with testosterone than that isolated from control female rats. These data suggest that the differences in hepatic AFB1 metabolism may be the underlying cause of the sex difference in toxicity and carcinogenicity of AFB1 observed in rats.  (+info)

Anaerobic oxidation of o-xylene, m-xylene, and homologous alkylbenzenes by new types of sulfate-reducing bacteria. (3/1546)

Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the delta subclass of the class Proteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum and Desulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, and o-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene, m-isoproyltoluene, benzoate, and m-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide.  (+info)

G protein activation by human dopamine D3 receptors in high-expressing Chinese hamster ovary cells: A guanosine-5'-O-(3-[35S]thio)- triphosphate binding and antibody study. (4/1546)

Despite extensive study, the G protein coupling of dopamine D3 receptors is poorly understood. In this study, we used guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]-GTPgammaS) binding to investigate the activation of G proteins coupled to human (h) D3 receptors stably expressed in Chinese hamster ovary (CHO) cells. Although the receptor expression level was high (15 pmol/mg), dopamine only stimulated G protein activation by 1.6-fold. This was despite the presence of marked receptor reserve for dopamine, as revealed by Furchgott analysis after irreversible hD3 receptor inactivation with the alkylating agent, EEDQ (N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline). Thus, half-maximal stimulation of [35S]-GTPgammaS binding required only 11.8% receptor occupation of hD3 sites. In contrast, although the hD2(short) receptor expression level in another CHO cell line was 11-fold lower, stimulation by dopamine was higher (2.5-fold). G protein activation was increased at hD3 and, less potently, at hD2 receptors by the preferential D3 agonists, PD 128,907 [(+)-(4aR,10bR)-3,4,4a, 10b-tetrahydro-4-propyl-2H,5H- [1]benzopyrano[4,3-b]-1, 4-oxazin-9-ol] and (+)-7-OH-DPAT (7-hydroxy-2-(di-n-propylamino)tetralin). Furthermore, the selective D3 antagonists, S 14297 ((+)-[7-(N, N-dipropylamino)-5,6,7, 8-tetrahydro-naphtho(2,3b)dihydro-2,3-furane]) and GR 218,231 (2(R, S)-(dipropylamino)-6-(4-methoxyphenylsulfonylmethyl)-1,2,3,4- tetrahydronaphtalene), blocked dopamine-stimulated [35S]GTPgammaS binding more potently at hD3 than at hD2 sites. Antibodies against Galphai/alphao reduced dopamine-induced G protein activation at both CHO-hD3 and -hD2 membranes, whereas GalphaS antibodies had no effect at either site. In contrast, incubation with anti-Galphaq/alpha11 antibodies, which did not affect dopamine-induced G protein activation at hD2 receptors, attenuated hD3-induced G protein activation. These data suggest that hD3 receptors may couple to Galphaq/alpha11 and would be consistent with the observation that pertussis toxin pretreatment, which inactivates only Gi/o proteins, only submaximally (80%) blocked dopamine-stimulated [35S]GTPgammaS binding in CHO-hD3 cells. Taken together, the present data indicate that 1) hD3 receptors functionally couple to G protein activation in CHO cells, 2) hD3 receptors activate G proteins less effectively than hD2 receptors, and 3) hD3 receptors may couple to different G protein subtypes than hD2 receptors, including nonpertussis sensitive Gq/11 proteins.  (+info)

In vitro reactions of butadiene monoxide with single- and double-stranded DNA: characterization and quantitation of several purine and pyrimidine adducts. (5/1546)

We have previously shown that butadiene monoxide (BM), the primary metabolite of 1,3-butadiene, reacted with nucleosides to form alkylation products that exhibited different rates of formation and different stabilities under in vitro physiological conditions. In the present study, BM was reacted with single-stranded (ss) and double-stranded (ds) calf thymus DNA and the alkylation products were characterized after enzymatic hydrolysis of the DNA. The primary products were regioisomeric N-7-guanine adducts. N-3-(2-hydroxy-3-buten-1-yl)adenine and N-3-(1-hydroxy-3-buten-2-yl)adenine, which were depurinated from the DNA more rapidly than the N-7-guanine adducts, were also formed. In addition, N6-(2-hydroxy-3-buten-1-yl)deoxyadenosine and N6-(1-hydroxy-3-buten-2-yl)deoxyadenosine were detected and evidence was obtained that these adducts were formed by Dimroth rearrangement of the corresponding N-1-deoxyadenosine adducts, not while in the DNA, but following the release of the N-1-alkylated nucleosides by enzymatic hydrolysis. N-3-(2-hydroxy-3-buten-1-yl)deoxyuridine adducts, which were apparently formed subsequent to deamination reactions of the corresponding deoxycytidine adducts, were also detected and were stable in the DNA. Adduct formation was linearly dependent upon BM concentration (10-1000 mM), with adduct ratios being similar at the various BM concentrations. At a high BM concentration (750 mM), the adducts were formed in a linear fashion for up to 8 h in both ssDNA and dsDNA. However, the rates of formation of the N-3-deoxyuridine and N6-deoxyadenosine adducts increased 10- to 20-fold in ssDNA versus dsDNA, whereas the N-7-guanine adducts increased only slightly, presumably due to differences in hydrogen bonding in ssDNA versus dsDNA. These results may contribute to a better understanding of the molecular mechanisms of mutagenesis and carcinogenesis of both BM and its parent compound, 1,3-butadiene.  (+info)

Monoclonal antibody 3F3 against conformational epitope of Torpedo acetylcholinesterase. (6/1546)

AIM: To study the type of epitope of native Torpedo acetylcholinesterase (AChE) directed by its monoclonal antibody (McAb) 3F3. METHODS: Enzyme-linked immunosorbent assay (ELISA) was used for the assay of the reaction between antigen and antibody. RESULTS: McAb 3F3 immunoreacted well with the native AChE, but not with the reduced- and alkylated-AChE (RA-AChE) at all. Soman did not interfere the binding of 3F3 with AChE molecule. The synthesized 24-peptide containing the active serine residue of the AChE active center did not react with McAb 3F3. CONCLUSION: 3F3 is a monoclonal antibody against the conformational epitope of Torpedo AChE active center, but dose not occupy the active serine residue of the enzyme.  (+info)

Use of methyl iodide for probing the polarity of the immediate environment of --SH groups in thiolenzymes. Reaction of methyl iodide with thiosubtilisin. (7/1546)

A new approach is proposed for probing the polarity of the immediate environment of -SH groups in thiolenzymes, based on the alkylation of the -SH group with methyl iodide, a relatively small and non-polar molecule. Rate and activation parameters (delta H*, delta S*) for the reaction of the enzyme are compared to those of glutathione, a simple -SH compound alkylated in aqueous medium. The enzyme and model compound are also reacted with iodoacetamide, a polar counterpart of the non-polar methyl iodide. The above method was applied to thiolsubtilisin, an artificial thiolenzyme. 1. The ratio of the rates of alkylation of thiolsubtilisin and glutathione is about 20 times as high with methyl iodide as with iodoacetamide. 2. delta H* and delta S* for enzyme alkylation, as compared to those for glutathione, are remarkably lower with methyl iodide whereas they are slightly higher with iodoacetamide. 3. delta H* and delta S* for alkylation of thiolsubtilisin with methyl iodide are similar to those found with glutathione in 40% dioxane/water mixture. 4. The activation enthalpy and entropy values for the reaction of thiolsubtilisin with D-2-bromo-n-valeramide are lower than those for glutathione reaction. Consequently, in this respect, D-2-bromo-n-valeramide is similar to methyl iodide rather than to iodoacetamide. It is concluded that the -SH group of thiolsubtilisin is located in an environment less polar than water. The concentration of methyl iodide in this non-polar layer is higher than in the bulk solution, which results in an enhanced reaction rate.  (+info)

Thermal effects on an enzymatically latent conformation of coagulation factor VIIa. (8/1546)

Activation of the zymogen factor VII yields an enzyme form, factor VIIa, with only modest activity. The thermal effect on this low activity of factor VIIa and its enhancement by the cofactor tissue factor was investigated. Factor VIIa activity measured with a chromogenic peptide substrate is characterized by an unusual temperature dependency which indicates that the activated protease exists in an equilibrium between a latent (enzymatically inactive) and an active conformation. As shown by calorimetry and activity measurements the thermal effects on factor VIIa are fully reversible below the denaturation temperature of 58.1 degrees C. A model for factor VIIa has been proposed [Higashi, S., Nishimura, H., Aita, K. & Iwanaga, S. (1994) J. Biol. Chem. 269, 18891-18898] in which the protease is supposed to exist primarily as a latent enzyme form because of the poor incorporation into the protease structure of the N-terminal Ile153 released by proteolytic cleavage during activation of factor VII. Binding of tissue factor to factor VIIa is assumed to shift the equilibrium towards an active conformation in which the N-terminal Ile153 forms a salt bridge with Asp343. We corroborate the validity of this model by: (a) chemical modification of factor VIIa; this suggests that the thermal effect on the equilibrium between the active and inactive conformation is reflected in the relative accessibility of the active site and the N-terminal Ile153; (b) measurements of factor VIIa binding to tissue factor indicating that complex formation is favoured by stabilization of the active conformation; and (c) activity measurements of a cross-linked factor VIIa-tissue factor complex; this showed that cross-linking stabilized the active conformation of factor VIIa and essentially prevented its thermally-induced transformation into the inactive state.  (+info)

TY - JOUR. T1 - Asymmetric Synthesis of α,β-Dialkyl-α-phenylalanines via Direct Alkylation of a Chiral Alanine Derivative with Racemic α-Alkylbenzyl Bromides. A Case of High Enantiomer Differentiation at Room Temperature. AU - Soloshonok, Vadim A.. AU - Tang, Xuejun. AU - Hruby, Victor J. AU - Van Meervelt, Luc. PY - 2001/2/8. Y1 - 2001/2/8. N2 - (Matrix Presented) This study demonstrates that the direct alkylation of a Ni(ll)-complex of the chiral Schiff base of alanine with (S)-o-[N-(N-benzylprolyl)amino]-benzophenone, with racemic α-alkylbenzyl bromides, is a synthetically feasible and methodologically advantageous approach to the target α,β-dialkylphenylalanines over previously reported methods. For the first time we report and rationalize a case of a high enantiomer differentiation process at room temperature.. AB - (Matrix Presented) This study demonstrates that the direct alkylation of a Ni(ll)-complex of the chiral Schiff base of alanine with ...
Global Ethyl Bromoacetate Sales Market Report 2018 1 Ethyl Bromoacetate Market Overview 1.1 Product Overview and Scope of Ethyl Bromoacetate 1.2 Classification of Ethyl Bromoacetate by Product Category 1.2.1 Global Ethyl Bromoacetate Market Size (Sales) Comparison by Type (2013-2025) 1.2.2 Global Ethyl Bromoacetate Market Size (Sales) Market Share by Type (Product Category) in 2017 1.2.3 Food Grade 1.2.4 Pharmaceutical Grade 1.3 Global Ethyl Bromoacetate Market by Application/End Users 1.3.1 Global Ethyl Bromoacetate Sales (Volume) and Market Share Comparison by Application (2013-2025) 1.3.2 Chemicals 1.3.3 Pharmaceuticals 1.3.4 Food Industry 1.3.5 Other 1.4 Global Ethyl Bromoacetate Market by Region 1.4.1 Global Ethyl Bromoacetate Market Size (Value) Comparison by Region (2013-2025) 1.4.2 United States Ethyl Bromoacetate Status and Prospect (2013-2025) 1.4.3 China Ethyl Bromoacetate Status and Prospect (2013-2025) 1.4.4 Europe Ethyl Bromoacetate Status and Prospect (2013-2025) 1.4.5 Japan Ethyl ...
Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion or a carbene (or their equivalents).[1] An alkyl group is a piece of a molecule with the general formula CnH2n+1, where n is the integer depicting the number of carbons linked together. For example, a methyl group (n = 1, CH3) is a fragment of a methane molecule (CH4). Alkylating agents use selective alkylation by adding the desired aliphatic carbon chain to the previously chosen starting molecule. This is one of many known chemical syntheses. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline.[2]. In medicine, alkylation of DNA is used in ...
Headline: Bitcoin & Blockchain Searches Exceed Trump! Blockchain Stocks Are Next!. Alkylation Catalysts Market analysis is provided for global market including development trends by regions, competitive analysis of the Alkylation Catalysts market. Alkylation Catalysts Industry report focuses on the major drivers and restraints for the key players. Alkylation Catalysts Market research report also provides granular analysis of the sales, market growth market share, segmentation, revenue forecasts and geographic regions of the market. Alkylation is the transfer of an alkyl group from one molecule to another. Alkylation of isobutane with olefins in the petroleum is an important industrial process to improve the octane number. As the most usually liquid acid catalysts, concentrated sulfuric acid (H2SO4) and hydrofluoric acid (HF) have potential environmental problem especially for the HF alkylation process.. Browse Detailed TOC, Tables, Figures, Charts and Companies Mentioned in Alkylation Catalysts ...
Here, we demonstrate that OTUD4 may serve as a master regulator of alkylation damage resistance through stabilization of the human AlkB homologues. A number of distinct lines of evidence support this role for OTUD4. First, OTUD4 interacts specifically with ALKBH2 and ALKBH3 and encodes a K48‐specific DUB (Fig 1). Consistently, ALKBH3 is subjected to K48‐linked ubiquitination and proteasomal degradation (Fig 2A-D). OTUD4 antagonizes ALKBH3 ubiquitination and stabilizes both ALKBH2 and ALKBH3 in vivo (Fig 2E-H). ALKBH3 protein levels do not correlate well with ALKBH3 mRNA levels in various tumor cell lines but do correlate with OTUD4 levels (Supplementary Fig S2). Finally, overexpression of ALKBH3 in PC‐3 cells, which depend primarily on ALKBH3 instead of ALKBH2 for alkylation damage resistance, is sufficient to rescue alkylation damage sensitivity upon loss of OTUD4 (Fig 7G).. What is most striking is that we find OTUD4 catalytic activity to be apparently dispensable for its stabilization ...
DNA repair of alkylation damage is defective in various cancers. This occurs through somatically acquired inactivation of the MGMT gene in various cancer types, including breast cancers. In addition to MGMT, the two E. coli AlkB homologs ALKBH2 and ALKBH3 have also been linked to direct reversal of alkylation damage. However, it is currently unknown whether ALKBH2 or ALKBH3 are found inactivated in cancer. Methylome datasets (GSE52865, GSE20713, GSE69914), available through Omnibus, were used to determine whether ALKBH2 or ALKBH3 are found inactivated by CpG promoter methylation. TCGA dataset enabled us to then assess the impact of CpG promoter methylation on mRNA expression for both ALKBH2 and ALKBH3. DNA methylation analysis for the ALKBH3 promoter region was carried out by pyrosequencing (PyroMark Q24) in 265 primary breast tumours and 30 proximal normal breast tissue samples along with 8 breast-derived cell lines. ALKBH3 mRNA and protein expression were analysed in cell lines using RT-PCR and
Tang, X.; Soloshonok, V.A.; Hruby, V.J., 2001: Asymmetric synthesis of alpha,beta-disubstituted-alpha-amino acids via direct alkylation of chiral amino acid derivatives with racemic sec-alkyl bromides
Chelated enolates are versatile nucleophiles for palladium-catalysed allylic alkylations. Even with complex allylic substrates the reaction proceed without significant isomerisation. This allows the stereoselective introduction of polyhydroxylated allylic sidechains into amino acids and peptides with retention of the olefin geometry ...
The CC-1065 and duocarmycin family of compounds are ultrapotent antitumour antibiotics which demonstrate activity in the picomolar range. These agents exert their biological effect through a sequence selective alkylation at the N3 position of adenine resulting in apoptosis. Despite the potential of this family to exert themselves as successful chemotherapeutic agents, a lack of clinical success has been observed for these compounds. This has been attributed to a lack of selectivity resulting in off-target side effects and toxicity. For this reason, research now focuses on ways in which these alkylating agents could realise their potential using tumour specific, targeted delivery strategies.. Herein, we investigate the use of a duocarmycin SA analogue, functionalised for solid phasesynthesis, in the design of conjugates for targeted delivery to cancerous tissue via the Thomsen-Friedenreich antigen (T-antigen). This antigen is overexpressed in 90% of primary human carcinomas, yet is cryptic in ...
The value derived for Henrys Law constant H relates to the properties of the substance oligomerisation and alkylation reaction products of 2-phenylpropene and phenol [EC no. 700-960-7]. Vapour pressure (VP) and water solubility (WS) were obtained from tests with different samples of the substance (see CSR Chapter 1.3). The molecular weight was determined as average molecular weight of the different commercial products of the substance taking into account the percentage of the components in the products and their respective molecular weights. The 90th percentile of these data was taken as characteristic average molecular weight for the substance (average MW 298 g/mol). The constant H for the substance oligomerisation and reaction product … is calculated using the vapour pressure of 0.044 Pa and the water solubility of 4 mg C/L (= 0.0134 mol/m³), both at 21°C (see Chapter 1.3.). Dimension of H is Pa*m³/mol. H = VP / WS x MW = 0.044 Pa / 4 mg/L x 298 g/mol = 3.278 Pa*m³/mol ...
Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact of alkylation damage across proteomes is poorly understood. We used Click chemistry and shotgun proteomics to profile the accumulation of proteome damage in human cells tre …
Isobutene/olefin alkylation is a major refinery process in which light hydrocarbons (isobutene and, mainly, C3 and C4 olefins) are converted to a high octane gasoline feedstock. Alkylate currently accounts for a key fraction of the total U.S. gasoline pool; in fact, concerns over emissions have led to an interest in increasing the amount of alkylate used in gasoline. However, environmental and safety concerns present a barrier to this increase, as current processes for alkylate production employ hazardous liquid acids. As yet, a practical process based on solid catalysts has not been identified ¿ conventional fixed bed processes have faced rapid catalyst aging and downtime for regeneration. This project will develop a novel reactor approach to solid-catalyzed isobutene/olefin alkylation in which olefin polymerization at the catalytic surface is limited, thereby avoiding the primary issue with solid catalyzed alkylation. Moreover, the proposed approach offers the potential for higher quality ...
TY - JOUR. T1 - Direct and stereoselective synthesis of β-mannosides by anomeric o-alkylation. AU - Takahashi, Daisuke. PY - 2016. Y1 - 2016. KW - Anomeric O-alkylation. KW - Glycosylation. KW - Stereoselective. KW - β-mannosylation. UR - http://www.scopus.com/inward/record.url?scp=84997542885&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=84997542885&partnerID=8YFLogxK. U2 - 10.4052/tigg.1608.6E. DO - 10.4052/tigg.1608.6E. M3 - Comment/debate. AN - SCOPUS:84997542885. VL - 28. SP - E119-E120. JO - Trends in Glycoscience and Glycotechnology. JF - Trends in Glycoscience and Glycotechnology. SN - 0915-7352. IS - 164. ER - ...
This thesis deals with secondary interactions in asymmetric catalysis and their impact on the outcome of catalytic reactions.. The first part revolves around the metal-catalyzed asymmetric allylic alkylation reaction and how interactions within the catalyst affect the stereochemistry. An OH-Pd hydrogen bond in Pd(0)-π-olefin complexes of hydroxy-containing oxazoline ligands was identified by density functional theory computations and helped to rationalize the contrasting results obtained employing hydroxy- and methoxy-containing ligands in the catalytic reaction. This type of hydrogen bond was further studied in phenanthroline metal complexes. As expected for a hydrogen bond, the strength of the bond was found to increase with increased electron density at the metal and with increased acidity of the hydroxy protons.. The second part deals with the use of hydroxy- and methoxy-containing phosphinooxazoline ligands in the rhodium- and iridium-catalyzed asymmetric hydrosilylation reaction. The ...
Alkylation is the process by when an alkyl group is added to a substrate molecule. Alkylation is a widely used technique in organic chemistry.
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Polymerase α is an essential enzyme mainly mediating Okazaki fragment synthesis during lagging strand replication. A specific point mutation in Schizosaccharomyces pombe polymerase α named swi7-1, abolishes imprinting required for mating-type switching. Here we investigate whether this mutation confers any genome-wide defects. We show that the swi7-1 mutation renders cells hypersensitive to the DNA damaging agents methyl methansulfonate (MMS), hydroxyurea (HU) and UV and incapacitates activation of the intra-S checkpoint in response to DNA damage. In addition we show that, in the swi7-1 background, cells are characterized by an elevated level of repair foci and recombination, indicative of increased genetic instability. Furthermore, we detect novel Swi1-, -Swi3- and Pol α- dependent alkylation damage repair intermediates with mobility on 2D-gel that suggests presence of single-stranded regions. Genetic interaction studies showed that the flap endonuclease Fen1 works in the same pathway as Pol ...
3,4-dihydropyrimidin-2(1H)-one compounds (DHPMs) possess extensive biological activities and are mainly prepared via Biginelli reaction and N-alkylation. In the present study, selective alkylation of N1 was investigated by using tetrabutylammonium hydroxide. In vitro cytotoxicity study on all synthesized compounds demonstrated that introduction of the aryl chain in the R3 as well as the low electron-donating group in the R1 of DHPMs contributed to the anti-proliferative potency. A larger value of the partition coefficient (Log P) and suitable polar surface area (PSA) values were both found to be important in order to maintain the antitumor activity. The results from in vivo study indicated the great potential of compound 3d to serve as a lead compound for novel anti-tumor drugs to treat glioma. Pharmacophore study regarding the structure-activity relations of DHPMs were also conducted. Our results here could provide a guide for the design of novel bioactive 3,4-dihydropyrimidin-2(1H)-one compounds.
1.1. Organolithium and Grignard reagents as nucleophiles - Metalation of halogenated compounds - Hydrogen/metal exchange - Halogen/metal exchange - General reactivity of electrophiles - Reaction of Organolithium and Grignard reagents - Diastereoselectivity of nucleophilic addition (Felkin-Anh, Cram - Enantioselectivity of organozinc/aldehyde additions 1.2. Reaction with organocopper reagents 1. Dithianes 2. O-Alkylated cyanohydranes 3. Alpha lithiated vinyl ethers 1.4. Homoenolate equivalents 1.5. Olefination of carbonyl compounds 1. Wittig reaction (Unstabilized ylides) 2. Horner-Emmons modification (stabilized ylides) 3. C.W. Still Modification 4. Peterson reaction 5. Methylenation of carbonyl compounds by Tebbe reagent 1. Reaction with saturated aldehydes and ketones 2. Reaction with α, β-unsaturated ketones 1. Preparation of enolates by α-deprotonation 2. Alkylation - Alkylation of enolates derived from 1,3-dicarbonyl compounds - Alkylation at γ position of 1,3-dicarbonyl compounds - ...
1993) have been devel- oped as generic reagents for introducing fluorine-18 into N-isopropyl groups by the reductive alkylation augmentin sf syrup direct alkylation of secondary amines, FAF488 appears to be augmetnin distributed and shows focally reduced intensity.
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TY - JOUR. T1 - Sulfhydryl Site-Specific Cross-Linking and Labeling of Monoclonal Antibodies by a Fluorescent Equilibrium Transfer Alkylation Cross-Link Reagent. AU - del Rosario, Renato B.. AU - Wahl, Richard L.. AU - Brocchini, Stephen J.. AU - Lawton, Richard G.. AU - Smith, Richard H.. PY - 1990/1/1. Y1 - 1990/1/1. N2 - The site-specific intramolecular cross-linking of sulfhydryls of monoclonal antibodies via a new class of equilibrium transfer alkylation cross-link (ETAC) reagents is described. Following complete or partial reduction of interchain disulfides with dithiothreitol (DTT), two murine IgG2a monoclonal antibodies, 225.28S and 5G6.4, were reacted with a,a-bis[(p-tolylsulfonyl)methyl]-m-aminoacetophenone (ETAC 1a) and a fluorescent conjugated derivative, sulforhodamine B m-(α,α-bis(p-tolylsulfonylmethyl) acetyl)anilide derivative (ETAC 1b). Reducing SDS-polyacrylamide gel electrophoresis analysis of the products from lb indicated the formation of S-ETAC-S interchain heavy and ...
D4337 - 89(2017) Standard Test Methods for Analysis of Linear Detergent Alkylates , linear alkylbenzenes, linear detergent alkylates ,,
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Visible-light-induced photoredox decarbonylative C-C bond formation with aldehydes is described for the first time. Minisci-type alkylation reactions of N-heteroarenes proceed smoothly at ambient temperature with air as the sole oxidant. The present sustainable protocol uses readily available organofluoresce 2019 Green Chemistry Hot Articles
Description: Subject matter wherein the hydrocarbon feed is treated prior to the alkylation reaction, e.g., by separating nonhydrocarbon therefrom, by separating the feed into several different fractions, etc ...
However, the simplest synthetic approach to the N-9 substituted guanine compounds involves the direct alkylation of appropriately substituted 2-aminopurines e.g. guanine derivatives. There are significant drawbacks to this approach as it always results in a mixture of N-9 and N-7 alkylation products. The undesirable N-7 isomers are produced in large amounts, which in turn necessitate tedious and in-efficient methods of separation such as silica gel chromatography in order to obtain the desired N-9 isomer at a favourable degree of purity. Use of halogenated purines can. hardly be selected as methods for industrial production, as their starting materials are expensive and difficult to acquire, and they demand a reaction with ammonia at high temperature and pressure in order to obtain guanine nucleosides, such as acyclovir, ganciclovir etc. Hence, it is highly desirable to develop a regioscpecific process for the manufacture of ganciclovir ...
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice ...
The registry of SVHC intentions until outcome aims to make interested parties aware of the substances for which an SVHC dossier is planned to be submitted to ECHA.. Member States, or ECHA at the request of the European Commission, may propose a substance to be identified as a substance of very high concern (SVHC) by preparing a dossier in accordance with the requirements set out in Annex XV to REACH.. Interested parties can follow the progress of a proposal through the SVHC identification process, from the notification of the intention until the outcome. The advance notice gives interested parties time to prepare for commenting later in the process.. Interested parties with relevant information on the identity or hazard properties of the substance may submit such information during the consultation.. ...
For REACH substances, inclusion in the list means that an informal hazard assessment for endocrine-disrupting properties either is under development or has been completed since the start of the implementation of the SVHC Roadmap in February 2013. For each substance, the table shows the assessing or evaluating Member State (submitter), the outcome and the suggested follow-up for the assessment, and the date of the latest update to the list entry. Other process details and hazard assessment outcome documents are also available and can be accessed through the Details icon. One possible outcome of such an assessment is that a substance is considered not to have ED properties. If the outcome is that the substance is considered to have ED properties, confirmation through the formal risk management and decision-making processes under REACH/BPR is needed before any regulatory action can be taken due to these properties. The intentions of authorities to submit a dossier to the formal REACH and CLP ...
The Ordinary Ethylated Ascorbic Acid 15% Solution 30ml Olağanüstü Kararlı, Doğrudan C Vitamini Formu Cildi aydınlatmaya ve zararlı çevresel faktörlere karşı
S-Adenosyl-L-Methionine (a.k.a., SAM, AdoMet) is a cofactor that is crucial to many biological processes. Specifically, SAM is a cationic sulfur-based alkylatin...
TY - JOUR. T1 - Alkylation of pyridine-3,5-dicarboxamide and pyridine-3,5-dicarbonitriles by radical substitution. AU - Kanomata, Nobuhiro. AU - Nagahara, Hisashi. AU - Tada, Masaru. PY - 1992/10/1. Y1 - 1992/10/1. N2 - Structural modification of NAD(P) model compounds, N,N,N′,N′ tetramethylpyridine-3,5-dicarboxamide (1), pyridine-3,5-dicarbonitrile (2), and 4-methylpyridine-3,5-dicarbonitrile (3), have been explored by the reaction with alkyl radicals such as the 1-adamantyl, tert-butyi, and isopropyl radicals. The alkyl substitutions of compounds 1, 2, and 3 with the 1-adamantyl and the fert-butyl radical gave both 2-mono and 2,6-disubsti-tution products, whereas the reaction of compound 2 with the isopropyl radical gave 2-mono 6c, 2,4-di 7c, 2,6-di 8c, and 2,4,6-trisubstitution 9c products.. AB - Structural modification of NAD(P) model compounds, N,N,N′,N′ tetramethylpyridine-3,5-dicarboxamide (1), pyridine-3,5-dicarbonitrile (2), and 4-methylpyridine-3,5-dicarbonitrile (3), have been ...
see article for more reactions. Abstract. A Cp*Ir complex bearing a functional bipyridonate ligand is a highly effective and versatile catalyst for the α-alkylation of ketones with primary alcohols under environmentally benign and mild conditions. Furthermore, this complex also exhibited a high level of catalytic activity for the α-methylation of ketones with methanol.. ...
Each sealed reaction vial contains either 75 µmol of BF3K reagent with 100 µmol of K2S2O8 or 250 µmol of tert-butyl peracetate. Typically, the reaction is performed with 6200K white LED or blue LED (450 nm). The alkylation production kit contains 2 sets of vials allowing the screening of two different substrates or 1 substrate in two solvents. Sparging reaction solvents with nitrogen or argon while transferring reagents is important to achieve highest conversions of product. See protocol diagram for instructions.. Protocol at 500 µl volume reaction condition. ...
Press release - Market Research Hub - Global Alkylation Catalyst Market Analysis By Application 2025 | Top Key Players Albemarle, BASF, CRI, Sinopec - published on openPR.com
sensitive.. Recommended solvents are DMSO or CHCl3 with or without H2O/TFA (0.1 ml of TFA in 2 ml of water). H2O/TFA can change the regioselectivity and conversion of the reaction.. Prepare a solution of ...
Starting from N-methyl-1-{(3S,4S)-4-[2-(trifluoromethyl)phenoxy]-3,4-dihydro-1H-isochromen-3-yl}methanamine (1) target compound 2 is prepared using a mild, direct alkylation approach with 2-fluoroethyl trifluoromethanesulfonate.
In this video Ill teach you why alpha-hydrogens are so acidic, and how we can use that property to do some cool organic reactions. Ill talk about keto-enol tautomerism, LDA (lithium diisopropyl amine), alpha-halogenation, alkylation, acylation, beta-alkylation, the aldol reaction, the Claisen condensation, the Robinson annulation, decarboxylation, and the malonic ester synthesis. --Dr. Mike Christiansen from Utah State University
Were found to alkylate all oxygens and nitrogens in nucleic acids , whereas a host of more moderately reactive electrophilic agents typically target nitrogens
Literature References: Antitumor antibiotic; alkylates DNA by interstrand crosslinking of the major groove. Isoln from Streptomyces sahachiroi: T. Hata et al., J. Antibiot. 7A, 107 (1954). Purification: H. Kamada et al., ibid. 8A, 187 (1955). Mechanism of action: J. W. Lown, K. C. Majumdar, Can. J. Biochem. 55, 630 (1977); T. Fujiwara, I. Saito, Tetrahedron Lett. 40, 315 (1999). Proposed structure: J. W. Lown, C. C. Hanstock, J. Am. Chem. Soc. 104, 3213 (1982). Identity with azinomycin B: E. J. Moran, R. W. Armstrong, Tetrahedron Lett. 32, 3807 (1991). Purification: K. Nagaoka et al., J. Antibiot. 39, 1527 (1986). Total structure as azinomycin B: K. Yokoi et al., Chem. Pharm. Bull. 34, 4554 (1986). ...
Seaview Health - Medical Clinic - Dr Jonathon Duffy, Dr Tatiana Cimpoesu, Dr Ei Thinzar Hlaing. Our medical practitioners / doctors provide high-quality personalised care to individuals and to families taking care of everyone at all stages of life.
Digitization process: Scanned using an Epson 750 as 1200 ppi, 48-bit, RGB, .tif; service master changed to black and white, levels and contrast adjusted, sharpened and cropped; derivative resampled to 3000 pixels on the long edge, 24-bit .jpg ...
Triarylborane Catalysed N-Alkylation of Amines with Aryl Esters - data - Nori V, Dasgupta A, Babaahmadi R, Carlone A, Ariafard A, Melen RL (2020). Cardiff University. 10.17035/d.2020.0117003506. ...
T. Mathew, S. Shylesh, S. N. Reddy, S. C. Peter, S. K. Date, B. S. Rao and S. D. Kulkarni, Redistribution of cations amongst different lattice sites in Cu1-xCoxFe2O4 ferrospinels during alkylation: magnetic study. , Cat. Lett. 93, 155 - 160 (2004 ...
An enantioselective synthesis of allenes through palladium-catalyzed asymmetric allylic alkylation using a chiral diaminophosphine oxide is described. The asymmetric allylic alkylations proceeded in the presence of a catalytic amount of lithium acetate at 4 °C, affording the chiral allenes in excellent yield with up to 99% ee. ...
Involvement of two endonuclease III homologs in the base excision repair pathway for the processing of DNA alkylation damage in Saccharomyces cerevisiae.
Dottavio-Martin, D.; Ravel, J.M., 1978: Radiolabeling of proteins by reductive alkylation with [14C]formaldehyde and sodium cyanoborohydride
Looking for online definition of ethylated in the Medical Dictionary? ethylated explanation free. What is ethylated? Meaning of ethylated medical term. What does ethylated mean?
Summary of Facts and Submissions. I. The appeal is from the decision of the Opposition Division to maintain the European patent 1 138 750 in amended form.. II. In opposition procedure the Opponent raised inter alia objections with regard to sufficiency of disclosure, lack of novelty and lack of inventive step and cited among others documents. D6: US-A-5 648 586. D7: STRATCO, The 1990 Alkylation Seminar:. J.-L. Nocca, C5s Selective Hydrogenation and Etherification. D8: STRATCO, The 1990 Alkylation Seminar: K. Masters, Amylene Alkylation. D9: NPRA Q&A Sessions: C5 alkylation questions (from 1989 to 1993). D17: STRATCO, The 1990 Alkylation Seminar:. J.-L. Nocca, Etherification. D18: STRATCO, The 1990 Alkylation Seminar:. J.-L. Nocca, Upgrading Alkylation Feedstocks by Hydrogenation. D21: WO-A-97/03148. III. In its decision the Opposition Division concluded inter alia that the Opponent was not allowed to start argumentation for the first time from a combination of documents D7,D17 and D18 at a very ...
The feasibility of distilling alkylation product and technical alkyl phenol in a continuous apparatus was established. The conditions for distilling the alkylation product and technical alkyl phenol was determined. In terms of its preliminary performance characteristics (sedimentation and increase in viscosity), additive BFK prepared on the basis of the target alkyl phenol distilled in the continuous apparatus surpasses the additive prepared on the basis of technical alkyl phenol with the periodic apparatus.(*DISTILLATION
TY - GEN. T1 - Modeling of benzene with ethylene alkylation. AU - Khlebnikova, Elena. AU - Dolganova, Irena. AU - Ivashkina, Elena. AU - Koshkin, Stanislav. PY - 2016/4/19. Y1 - 2016/4/19. N2 - The paper considers the benzene alkylation with ethylene model development with the use of zeolite catalyst. A list of reactions occurring in the alkylation reactor was made and the thermodynamic possibility of determination of these reactions by the change of Gibbs energy was defined. The paper presents the hydrocarbons transformation scheme, which includes the grouping of components on the basis of their reactivity and the degrees of compensation values of the corresponding reactions. Drawing on the obtained data the authors developed the kinetic model of the alkylation of benzene with ethylene.. AB - The paper considers the benzene alkylation with ethylene model development with the use of zeolite catalyst. A list of reactions occurring in the alkylation reactor was made and the thermodynamic ...
The first direct intermolecular regiospecific and highly enantioselective a-allylic alkylation of linear aldehydes by a combination of achiral bench-stable Pd0 complexes and simple chiral amines as co-catalysts is disclosed. The co-catalytic asymmetric chemoselective and regiospecific a-allylic alkylation reaction is linked in tandem with in situ reduction to give the corresponding 2-alkyl alcohols with high enantiomeric ratios (up to 98:2 e.r.; e.r.=enantiomeric ratio). It is also an expeditious entry to valuable 2-alkyl substituted hemiacetals, 2-alkyl-butane-1,4-diols, and amines. The concise co-catalytic asymmetric total syntheses of biologically active natural products (e.g., Arundic acid) are disclosed.. ...
TY - JOUR. T1 - Enolate and Other Carbon Nucleophile Alkylation Reactions using 1,2-Cyclic Sulfates as Terminal Epoxide Equivalents. AU - Hoye, Thomas R. AU - Crawford, Khushrav B.. PY - 1994/2/1. Y1 - 1994/2/1. N2 - Enolates of esters and amides as well as α-sulfonyl-, α-cyano-, and α-phosphonyl-substituted anions react with cyclic sulfate 1 to give hydroxylated products arising from nucleophilic attack, on this terminal epoxide equivalent, at the primary carbon.. AB - Enolates of esters and amides as well as α-sulfonyl-, α-cyano-, and α-phosphonyl-substituted anions react with cyclic sulfate 1 to give hydroxylated products arising from nucleophilic attack, on this terminal epoxide equivalent, at the primary carbon.. UR - http://www.scopus.com/inward/record.url?scp=0012518614&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0012518614&partnerID=8YFLogxK. U2 - 10.1021/jo00082a005. DO - 10.1021/jo00082a005. M3 - Letter. AN - SCOPUS:0012518614. VL - 59. SP - 520. EP - ...
Alkylation reactions represent an important organic transformation to form C-C bonds. In addition to conventional approaches with alkyl halides or sulfonates as alkylating agents, the use of unactivated olefins for alkylations has become attractive from both cost and sustainability viewpoints. This Review summarizes transition-metal-catalyzed alkylations of various
0019] In other embodiments the adjusting is done by changing a ratio of isoparaffin to olefin in a feed to the alkylation reactor. In general, lowering the molar ratio of isoparaffin to olefin in the feed will produce a higher level of C5+ hydrocarbons in the process unit that boil above 280° F. (137.8 degree Celsius). In one embodiment, the molar ratio of isoparaffin to olefin in the feed while operating the alkylation reactor in the alkylate mode is from 4:1 to 100:1, such as from 4:1 to 50:1, or from 4:1 to 20:1; and the molar ratio of isoparaffin to olefin in the feed while operating the alkylation reactor in the distillate mode is a lower molar ratio from that used during the alkylate mode, from 0.25:1 to 25:1, such as from 0.25:1 to 20:1, or 0.25:1 to 10:1. In a different embodiment the molar ratio of isoparaffin to olefin in the feed is approximately the same while operating in both the alkylate mode and the distillate mode. In one embodiment, the control system connected to the ...
Looking for online definition of alkylate in the Medical Dictionary? alkylate explanation free. What is alkylate? Meaning of alkylate medical term. What does alkylate mean?
Title: Chiral Pyrrolidine-Based Salen Ligands for the Enantioselective Alkylation of Aromatic Aldehydes. VOLUME: 4 ISSUE: 2. Author(s): M. Elisa da Silva Serra, Dina Murtinho, Albertino Goth and A. M. dA. Rocha Gonsalves. Affiliation:Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal.. Keywords:Pyrrolidine, diamine, Salen, diethylzinc, enantioselective, alkylation. Abstract: A new type of Salen ligands derived from (2R, 3R)-N-benzyl-2,3-diaminopyrrolidine and aromatic hydroxyaldehydes was synthesized and tested in the enantioselective alkylation of aromatic aldehydes with diethylzinc, moderate selectivity being observed. This study represents the application of a new type of Zn- Salen ligands and opens the way to exploring these promising new structures in other enantioselective and biological processes. ...
TY - JOUR. T1 - Thermodynamic analysis of benzene alkylation with propylene. AU - Chudinova, Alena A.. AU - Nurmakanova, Asem E.. AU - Salishcheva, Anastasiya A.. AU - Ivashkina, Elena N.. PY - 2015. Y1 - 2015. N2 - Relevance of the research is caused by broad application of alkylation in industry and the necessity to develop a mathematical model adequate on the predicting ability and suitable for solving the technological problems in producing cumene with aluminum chloride. The main aim of the research is to define and to study the thermodynamic and kinetic regularities of benzene alkylation with propylene in the presence of aluminum chloride applying the methods of quantum chemistry. The methods used in the study: electronic-structural method based on density functional theory (DFT, DFT) at B3LYP. Search for transition state of the reaction in the presence of Lewis acids was performed by QST2 at B3LYP / 631 ++ G(d,p) and LSDA / 631 ++ G(d,p). The results. The thermodynamic parameters of the ...
Alkyltransferase-like proteins (ATLs) share functional motifs with the cancer chemotherapy target O(6)-alkylguanine-DNA alkyltransferase (AGT) and paradoxically protect cells from the biological effects of DNA alkylation damage, despite lacking the reactive cysteine and alkyltransferase activity of AGT. Here we determine Schizosaccharomyces pombe ATL structures without and with damaged DNA containing the endogenous lesion O(6)-methylguanine or cigarette-smoke-derived O(6)-4-(3-pyridyl)-4-oxobutylguanine. These results reveal non-enzymatic DNA nucleotide flipping plus increased DNA distortion and binding pocket size compared to AGT. Our analysis of lesion-binding site conservation identifies new ATLs in sea anemone and ancestral archaea, indicating that ATL interactions are ancestral to present-day repair pathways in all domains of life. Genetic connections to mammalian XPG (also known as ERCC5) and ERCC1 in S. pombe homologues Rad13 and Swi10 and biochemical interactions with Escherichia coli ...
TY - JOUR. T1 - In vivo DNA alkylation and somatic cell mutation in Drosophila.(共著). AU - Negishi, Tomoe. PY - 1992. Y1 - 1992. M3 - Article. VL - 272. SP - 275. EP - 275. JO - Mutation Res.. JF - Mutation Res.. ER - ...
Expression of the Escherichia coli aidB gene is induced in vivo by alkylation damage in an ada-dependent pathway and by anaerobiosis or by acetate at pH 6.5 in an ada-independent fashion. In this report, we present data on aidB gene structure, function, and regulation. The aidB gene encodes a protein of ca. 60 kDa that is homologous to several mammalian acyl coenzyme A dehydrogenases. Accordingly, crude extracts from an aidB-overexpressing strain showed isovaleryl coenzyme A dehydrogenase activity. aidB overexpression also reduced N-methyl-N-nitro-N-nitrosoguanidine-induced mutagenesis. Both ada- and acetate/pH-dependent induction of aidB are regulated at the transcriptional level, and the same transcriptional start point is used for both kinds of induction. Ada protein plays a direct role in aidB regulation: methylated Ada is able to bind to the aidB promoter region and to activate transcription from aidB in an in vitro transcription-translation system using crude E. coli extracts.
Although visible light photoredox catalysis has emerged as a powerful tool for the construction of C-C bonds, common catalysts and/or their photoexcited states suffer from low redox potentials, limiting their applicability to alkyl radical generation from substrates with activated carbon-halogen bonds. Radic
The first part of this thesis addresses the design and synthesis of amine building blocks accomplished by applying two different synthetic procedures, both of which were developed using solid-phase chemistry. Chapter 1 presents the first of these methods, entailing a practical solid-phase parallel synthesis route to N-monoalkylated aminopiperidines and aminopyrrolidines achieved by selective reductive alkylation of primary and/or secondary amines. Solid-phase NMR spectroscopy was used to monitor the reactions for which a new pulse sequence was developed. The second method, reported in Chapter 2, involves a novel approach to the synthesis of secondary amines starting from reactive alkyl halides and azides. The convenient solid-phase protocol that was devised made use of the Staudinger reaction in order to accomplish highly efficient alkylations of N-alkyl phosphimines or N-aryl phosphimines with reactive alkyl halides.. The second part of the thesis describes the design and synthesis of three ...
The N-alkylation of amines constitutes one of the most widely applied transformations in synthetic chemistry, but established methods often utilise non-renewable feedstocks and must be adapted for a post fossil fuel world. This review is focused on emerging methodologies in which redox surrogate reagents to carbonyl compounds are used which may be more readily sourced from nature. The review considers both chemocatalytic and biocatalytic approaches and considers challenges such as application and the development of sustainable methodology with low carbon impact ...
Epichlorohydrin (ECH) is a DNA bifunctional alkylating agent that has been shown to form DNA inter-strand cross-links in vitro at the N7 position of guanines at the 5-GNC and 5-GC consensus sequences. We used the quantitative polymerase chain reaction (QPCR) to monitor the formation of in vivo ECH lesions in 6C2 chicken erythroid progerutor cells. Three distinct loci were investigated in order to determine the effect of ECH reactivity in different levels of chromatin condensation. The sites consisted of an open locus of the nuclear genome, a closed locus of the nuclear genome, and a naked locus of the mitochondrial genome. We found that ECH alkylation was preferentially targeted towards the nuclear sites and that chromatin structure had no effect upon ECH reactivity. Repair assays of the three sites revealed that there appears to be no repair of ECH lesions in the nuclear genome.
Biosketch. B.Sc. Biochemistry, Aberdeen University, Scotland 1974 Ph.D. Molecular Biology, Imperial Cancer Research Fund and University College, London University, England 1978 Director, MIT Center for Environmental Health Sciences, MIT, 2001 Affiliate, MIT Center for Cancer Research, 2001 Adjunct Professor of Toxicology, Harvard School of Public Health, 2001 Executive Committee, MIT Computational and Systems Biology Initiative (CSBi). Research Summary. Research in the Samson lab is aimed at understanding how cell, tissues, animals and ultimately people respond upon exposure to environmental toxicants in general, and alkylating agents in particular. A wide variety of DNA repair pathways provide protection against DNA alkylation damage and it is now clear that a multitude of other pathways are important for cellular recovery. Our goal is to understand how these pathways function, how they are regulated, and how they integrate to determine the ultimate biological and health consequences of ...
Peptoids & N-Alkylated Peptides Alkylating the Nitrogen of a peptide bond is one modern approach to equip peptide based biopharmaceuticals with proteolytic stability and altered activity. They can be synthesized in a repetitive manner, just as peptides by
To investigate the mechanism of cell death induced by the N-alkylated prodigiosin analogue, 2,2′-[3-methoxy-1′amyl-5′-methyl-4-(1′′-pyrryl)] dipyrryl-methene (MAMPDM) in S-180 and EL-4 tumour cell lines. Effect of MAMPDM on cell viability was assessed by MTT dye conversion. Induction of apoptosis was assessed by monitoring caspase 3 activity using a fluorogenic substrate, fragmentation of DNA by gel electrophoresis and sub-diploid DNA containing cells by flowcytometry. Necrosis was estimated by flowcytometric analysis of the uptake of propidium iodide. MAMPDM inhibited the proliferation of murine fibrosarcoma, S-180 cells and induced cell death. Investigations into the mechanism of cell death by MAMPDM in S-180 cells showed absence of hallmarks of apoptotic cell death such as activation of caspase 3, DNA fragmentation and presence of cells with sub-diploid DNA content. However, there was a rapid loss of membrane integrity as assessed by uptake of propidium iodide, which is characteristic of
Zeolites are solid acid catalysts currently of use in many industrial chemical processes. A major challenge to zeolite catalysis is the design of catalysts with improved lifetime. As we will show for the alkylation reaction, catalyst lifetime is tuned by choice of reaction conditions, selection of zeolite microporous structure and catalyst acidity. The alkylation reaction produces gasoline from the reaction of isobutane with light alkene molecules. There is need to develop improved heterogenous catalysts for this process that currently is catalyzed by hazardous liquid acids.. ...
Repeated dose toxicity information is available from an oral sub-chronic toxicity study (OECD 408 - Repeated Dose 90-day Oral Toxicity Study in Rodents, see below). For inhalation exposure, route-to-route extrapolation is applied. The dose descriptor starting point is converted into the modified dose descriptor starting point using the following equation (see Guidance IR&CSA Chapter R.8, Figure R. 8-3, p 21): correctedinhalatory NOAEC = oral NOAEL x 1 / 0.38 (m³ / kg / d) x (Absoral-rat /Absinh-human) x 6.7 m³ (RV: 8h, standard) / 10 m³ (RV: 8h, light work) = 40 x 1/0.38 x 0.5/1 x 6.7/10 = 35.26 mg/m³ ...
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Deamination Chemistry: Nucleic Acid Alkylation & Cross-Linking. We have been interested in two types of deaminations and their relation to modifications of DNA bases. The first type relates to the deamination of amines (and derivatives) and their role in the alkylation of DNA. The other relates to the deamination of amino groups in DNA bases. Both of these processes have important biological consequences. In this context, we have been studying decomposition pathways from the bottom up beginning with diazonium ions. We proposed a new bonding model and established crucial links between theory and experiment. Current studies of diazonium ions focus on the mechanisms of their SN chemistry and studies of the diazonium ions of DNA bases. To address questions as to the consequences of alkylation on DNA and RNA structure and properties, our initial studies have focused on studies of base pairing. Non-Synergistic Bonding & Thymine Dimerization. Our analysis of H-bonded Adenine-Thymine, A=T, suggests ...
Alkylating agents exert a wide range of biological effects in both pro- and eukaryotes and there is ever increasing evidence that these effects are mediated via alkylation at the O6position of...
An efficient catalytic system for the alkylation of amines with either alcohols or amines under mild conditions has been developed, using cyclometallated iridium complexes as catalysts. The method has broad substrate scope, allowing for the synthesis of a diverse range of secondary and tertiary amines with good to excellent yields. By controlling the ratio of substrates, both mono- and bis-alkylated amines can be obtained with high selectivity. In particular, methanol can be used as the alkylating reagent, affording N-methylated products selectively. A strong solvent effect is observed for the reaction.
TY - JOUR. T1 - Theoretical study of the alkyl derivative C37H50N4O4 molecule for use as a stable molecular rectifier. T2 - E-MRS 2002, Symposium A. AU - Mizuseki, Hiroshi. AU - Niimura, Kenji. AU - Majumder, Chiranjib. AU - Kawazoe, Yoshiyuki. N1 - Funding Information: The authors would like to express their sincere thanks to the Center for Computational Materials Science of the Institute for Materials Research, Tohoku University, for their continuous support of the HITAC SR8000-G1/64 supercomputing facilities. This study was performed through Special Coordination Funds for Promoting Science and Technology from the Ministry of Education, Culture, Sports, Science and Technology of the Japanese Government.. PY - 2003/3. Y1 - 2003/3. N2 - The realization of a molecular device with a unimolecular rectifying function is one of the most important requirements in nanotechnology. In the present study, the geometric and electronic structure of the alkyl derivative molecule C37H50N4O4 has been ...
Sodium triacetoxyborohydride has emerged as one of the reagents used most frequently for carrying out reductive amination of carbonyl compounds, a reaction that is also known as reductive alkylation of amines. A disadvantage of sodium triacetoxyborohydride is its poor solubility, and that product isolation requires an aqueous quench followed by liquid-liquid extraction and column chromatography.. Biotage® MP-Triacetoxyborohydride was developed to perform in a manner similar to that of sodium triacetoxyborohydride, while simplifying reagent handling and product purification. Moreover, for many of these reactions, a scavenger resin may be added for one-pot purification of the product.. ...
Xiao J,KaiZhao,TeckPengLoh. Highly Enantioselective Intermolecular Alkylation of Aldehydes with Alcohols by Cooperative Catalysis of Diarylprolinol Silyl Ether with Brønsted Acid[J]. Chemistry-An Asian Journal,2011,6:2890 ...
TY - JOUR. T1 - Iron-Catalyzed Arylation of Aromatic Ketones and Aldehydes Mediated by Organosilanes. AU - Savela, Risto. AU - Majewski, Marcin. AU - Leino, Reko. PY - 2014. Y1 - 2014. N2 - A simple and efficient iron-catalyzed method for arylation of aromatic carbonyl compounds is reported. The use of 4% FeCl3 or Fe(acac)(3) as the catalyst, in combination with a slight excess of chlorotrimethylsilane and triethylsilane, chlorination of benzylic ketones and aldehydes with subsequent Friedel-Crafts alkylation of arenes is achieved. Although the method is limited by the general constraints associated with Friedel-Crafts alkylation reactions, robust applications for the synthesis of pharmaceutical intermediates and so on can be envisioned.. AB - A simple and efficient iron-catalyzed method for arylation of aromatic carbonyl compounds is reported. The use of 4% FeCl3 or Fe(acac)(3) as the catalyst, in combination with a slight excess of chlorotrimethylsilane and triethylsilane, chlorination of ...
The elucidation of signalling pathways relies heavily upon the identification of protein kinase substrates. Recent investigations have demonstrated the efficacy of chemical genetics using ATP analogues and modified protein kinases for specific substrate labelling. Here we combine N(6) -(cyclohexyl)ATPγS with an analogue-sensitive cdk2 variant to thiophosphorylate its substrates and demonstrate a pH-dependent, chemoselective, one-step alkylation to facilitate the detection or isolation of thiophosphorylated peptides.
Nayfeh, S and Dowden, E, Effects of alkylation of rna synthesis by ehrlich ascites tumors in vivo. Abstr. (1969). Subject Strain Bibliography 1969. 982 ...
Phenol alkylation catalyst-2-Kairui Environmental Protection Technology Co., Ltd.-Representativemodel:KC103,KC103A、KC103B,etc. Mainuse:Usedascatalystinalkylationreactionbyphenolssuchasphenol,cresolwithoctylene,nonylene
Reports emphasize developments in process technology for Alkylation for Motor Fuels that have potential implications for the chemical and energy industries
Axens has signed an agreement with ExxonMobil Catalysts and Licensing (ExxonMobil) to sublicence the latters sulfuric acid alkylation technology.
Alkylation, in petroleum refining, chemical process in which light, gaseous hydrocarbons are combined to produce high-octane components of gasoline. The light hydrocarbons consist of olefins such as propylene and butylene and isoparaffins such as isobutane. These compounds are fed into a reactor,
ALKBH2 - ALKBH2 (Myc-DDK-tagged)-Human alkB, alkylation repair homolog 2 (E. coli) (ALKBH2), transcript variant 3 available for purchase from OriGene - Your Gene Company.
Preview - Issue 42/2006 Angewandte Chemie Highlights Asymmetric Synthesis Tsuji-Trost Allylic Alkylation with Ketone Enolates M. Braun and T. Meier An FeVI Nitride: There Is Plenty of Room at the Top! High Oxidation States P. J. Chirik 1 Reviews Green Chemistry 1 Hydrogen Peroxide Synthesis: An Outlook beyond the Anthraquinone Process J. L. G. Fierro et al. Communications Microporous Materials 2 F. P. Gabba0 et al. Molecular Recognition 3 F. W. Scheller et al. Oxidative C C Coupling 4 Hydrocarbon Uptake in the Alkylated Micropores of a Columnar Supramolecular Solid (Cover Picture) 2 A Bifunctional Molecularly Imprinted Polymer (MIP): Analysis of Binding and Catalysis by a Thermistor Intermolecular Oxidative Enolate Heterocoupling P. S. Baran and M. P. DeMartino Antibiotics Total Synthesis of Platensimycin 3 K. C. Nicolaou et al. Heterogeneous Catalysis S. L. Buchwald et al. Domino Cu-Catalyzed C N Coupling/ Hydroamidation: A Highly Efficient Synthesis of Nitrogen Heterocycles Natural Products ...
Several of the pathways of metabolism of the suspected carcinogen acrylonitrile (AN) were identified previously in this laboratory with the use of subcellular fractions and purified enzymes (Guengerich, F. P., Geiger, L. E., Hogy, L. L., and Wright, P. L., Cancer Res., 41: 4925-4933, 1981). In order to establish the relative contributions of the various pathways leading to activated and detoxicated products, we examined AN metabolism in isolated Fischer 344 rat hepatocytes as a model. Reduced glutathione (GSH) was depleted, and cell viability was lost in an AN concentration-dependent manner. The major GSH adduct formed at all AN concentrations was identified as S-(2-cyanoethyl)GSH using thin-layer and high-performance liquid chromatography. Acid hydrolysis and amino acid analysis of labeled hepatocellular protein revealed S-(2-carboxyethyl)-cysteine as the major adduct formed, indicating direct alkylation of cysteinyl residues by AN. 2-Cyanoethylene oxide accumulated in the hepatocyte ...
formula I or ketoamide intermediates to prepare compounds of formula I is to to add 1- 20 equivalents but most preferably 5 equivalents of a commercially available solution of 32% peracetic acid in dilute aq acetic acid to the reaction flask containing the completed reaction described in Step A. The reaction is typically stirred at the same temperature at which the alkylation reaction was conducted (for the Step A reactions with an acid chloride in THF -78° and for the step A reactions in DMF ~ -42°) for a period of Ih and then allowed to warm to ambient temperature if not already at that tmeperature. The reaction mixture is then either allowed to react further or immediately diluted with saturated aq. ammonium chloride and EtOAc. For relatively insoluble acid products which precipatate, the resultant precipitate is isolated by filtration as the oxoacetyl product ZC(O)C(O)Y. For organic soluble acid products, the acid is extracted into the organic layer and the layers separated. The organic ...
Steroids: Nilevar a ethylated version of nortestosterone. is the C-17 alpha ethylated derivative of nortestosterone (nandrolone). This modification renders
1D86: Structural consequences of a carcinogenic alkylation lesion on DNA: effect of O6-ethylguanine on the molecular structure of the d(CGC[e6G]AATTCGCG)-netropsin complex.
Tubes have been incubated thirty min at 37 C during the dark. Then 1 uL of 500 mM DTT was Epothilone added to quench the alkylation response. Upcoming four. five uL of 200 mM CaCl2 were added to just about every tube. An extra five uL of 500 mM Tris HCl had been additional to sustain the pH and ionic strength. Ultimately, ten ug of trypsin or chymotrypsin dissolved in one mM HCl had been additional to every single tube. Tubes had been incubated 24 h at 37 C after which frozen at 30 C until eventually preparation for mass spectrometry. Digestion of venoms with Glu C Reduction and alkylation of venoms were carried out as described over, except that as opposed to 500 mM Tris HCl, 167 mM phosphoric acid NaOH was applied. Additionally, the enzyme was dissolved in ultrapure water, as opposed to in one mM HCl. This enabled the enzyme to cleave proteins adjacent to aspartic acid residues, likewise as glutamate residues. Once the enzyme was dissolved in one mM HCl, it cleaved subsequent to glutamate ...
Name: AP Chemistry Period: Date: Dr. Mandes The Following Questions Represent Potential Types Of Quiz Questions. Please Answer Each Question Completely And Thoroughly. The Solutions Will Be Posted On-line On Monday. 5. Please Do #18 In Chapter 12 Of Your Text. A. This Increases The [H 2], Which Will Increase The Rate, But Has No Effect On K B. Due To Arrhenius Equation, Changing Temperature ... Apr 2th, ...
Purchase your copy of ASTM UOP382 - 81 as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards available online in electronic and print formats.
Alkylation[edit]. The most industrially significant amines are prepared from ammonia by alkylation with alcohols:[5] ... Amine alkylation Amines Degree of substitution increases Schotten-Baumann reaction Amide Reagents: acyl chlorides, acid ... Alkylation, acylation, and sulfonation[edit]. Aside from their basicity, the dominant reactivity of amines is their ... Such reactions, which are most useful for alkyl iodides and bromides, are rarely employed because the degree of alkylation is ...
N-Alkylation[edit]. N-Methylation of aniline with methanol at elevated temperatures over acid catalysts gives N-methylaniline ... The largest scale industrial reaction of aniline involves its alkylation with formaldehyde. An idealized equation is shown: 2 C ...
Friedel-Crafts alkylation involves the alkylation of an aromatic ring with an alkyl halide using a strong Lewis acid, such as ... Friedel-Crafts alkylation has been hypothesized to be reversible. In a retro-Friedel-Crafts reaction or Friedel-Crafts ... Reaction conditions are similar to the Friedel-Crafts alkylation. This reaction has several advantages over the alkylation ... In a green chemistry variation aluminium chloride is replaced by graphite in an alkylation of p-xylene with 2-bromobutane. This ...
Silicotungstic acid is used to manufacture ethyl acetate by the alkylation of acetic acid by ethylene: C2H4 + CH3CO2H → CH3CO2C ... Alkylation of carboxylate salts[edit]. Although not widely employed for esterifications, salts of carboxylate anions can be ... Another variation is the Fráter-Seebach alkylation. Other reactions[edit]. *Phenyl esters react to hydroxyarylketones in the ...
Thus, the alkylation of linear alkenes, even 1-alkenes such as 1-dodecene, gives several isomers of phenyldodecane. Under ideal ... Bipin V. Vora; Joseph A. Kocal; Paul T. Barger; Robert J. Schmidt; James A. Johnson (2003). "Alkylation". Kirk‐Othmer ... They were prepared by the Friedel-Crafts alkylation of benzene with 'propylene tetramer' (also called tetrapropylene) followed ...
It results from the alkylation of isobutane by propylene. Often referred to as "alkylate", it is blended with other gasoline ... Bipin V. Vora; Joseph A. Kocal; Paul T. Barger; Robert J. Schmidt; James A. Johnson (2003). "Alkylation". Kirk‐Othmer ...
Cymenes can be produced by alkylation of toluene with propylene. Vora, Bipin V.; Kocal, Joseph A.; Barger, Paul T.; Schmidt, ... Robert J.; Johnson, James A. (2003). "Alkylation". Kirk-Othmer Encyclopedia of Chemical Technology. Kirk‐Othmer Encyclopedia of ...
This compound and some related alkylbenzene are produced industrially by alkylation of benzene with the corresponding alkenes ... "Alkylation". Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.0112112508011313.a01.pub2.CS1 maint: uses ...
Bipin V. Vora; Joseph A. Kocal; Paul T. Barger; Robert J. Schmidt; James A. Johnson (2003). "Alkylation". Kirk‐Othmer ... Isobutane is the principal feedstock in alkylation units of refineries. Using isobutane, gasoline-grade "blendstocks" are ...
Cymene is also produced by alkylation of toluene with propylene. It is a constituent of a number of essential oils, most ... "Alkylation". Kirk-Othmer Encyclopedia of Chemical Technology. Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/ ...
Bipin V. Vora, Joseph A. Kocal, Paul T. Barger, Robert J. Schmidt, James A. Johnson (2003). "Alkylation". Kirk‐Othmer ... Propylene, isobutene, and amylenes are feedstock in alkylation units of refineries. Using isobutane, blendstocks are generated ...
The original route for manufacturing of cumene was by alkylation of benzene in the liquid phase using sulfuric acid as a ... Commercial production of cumene is by Friedel-Crafts alkylation of benzene with propylene. Cumene producers account for ... "Alkylation". Kirk-Othmer Encyclopedia of Chemical Technology. Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/ ...
The process is conducted in alkylation units in the presence of acid catalysts. It can also be produced from isobutylene by ... Isooctane is produced on a massive scale in the petroleum industry by alkylation of isobutene with isobutane. ... "Alkylation". Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.0112112508011313.a01.pub2. Dimerization of ...
Vora, Bipin V.; Kocal, Joseph A.; Barger, Paul T.; Schmidt, Robert J.; Johnson, James A. (2003). "Alkylation". Kirk-Othmer ... Cymenes can be produced by alkylation of toluene with propylene. Hashemi, Mohammad; Ehsani, Ali; Hosseini Jazani, Nima; ...
Alkylation. Major chemical intermediates from the alkylation with ethylene is ethylbenzene, precursor to styrene. Styrene is ... alkylation, 5) hydration, 6) oligomerization, and 7) hydroformylation. In the United States and Europe, approximately 90% of ...
O-alkylation. Pyridine N-oxides react with alkyl halides to the O-alkylated product Bis-ter-pyridine derivatives adsorbed on ...
The Tsuji-Trost reaction (also called the Trost allylic alkylation or allylic alkylation) is a palladium-catalysed substitution ... Allylic alkylation." J. Am. Chem. Soc. 1973, 95, 292-294. doi:10.1021/ja00782a080. Rios, Itzel Guerrero; Rosas-Hernandez, ... Trost, B. M.; Strege, P. E. "Asymmetric induction in catalytic allylic alkylation." J. Am. Chem. Soc. 1977, 99, 1649-1651. doi: ... The enantioselective version of the Tsuji-Trost reaction is called the Trost asymmetric allylic alkylation (Trost AAA) or ...
Alkylation unit. This reacted isobutane with butenes, collected from across the refinery processes, in the presence of a ...
... α-alkylation… Mannich... Michael [a]ddition... and α-amination… [reactions] of carbonyl compounds. In the literature, this ...
Alkylation processes have since been used to produce gasoline for motors, as engines became more powerful. Alkylation can be a ... Dutton, John A. "Alkylation". FSC 432 Petroleum Processing. Penn State. Retrieved September 22, 2018. "Alkylation is an ... During the alkylation process, light molecular weight iso-paraffins such as isobutane can be combined with C3-C4 olefins to ... This alkylation process was discovered in 1932 and commercialized in 1938. Ipatieff and Pines were trying to understand complex ...
AlkylationEdit. Alkyl nitriles are sufficiently acidic to form nitrile anions, which alkylate a wide variety of electrophiles.[ ...
C-alkylationEdit. C-alkylation is a process for the formation of carbon-carbon bonds. For alkylation at carbon, the ... alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a ... N-and P-alkylationEdit. N- and P-alkylation are important processes for the formation of carbon-nitrogen and carbon-phosphorus ... In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the ...
AlkylationEdit. Ethers can be alkylated at oxygen only with difficulty, but sulfides are readily alkylated to give stable ... Sulfides are typically prepared by alkylation of thiols: R-Br + HS-R′ → R-S-R′ + HBr. Such reactions are usually conducted in ... In analogy to their easy alkylation, sulfides bind to metals to form thioether complexes. They are classified as soft ligands, ...
for inducing alkylation reactions.[verification needed] Blass, Benjamin E. (2002). "KF/Al2O3 Mediated organic synthesis". ... A Versatile Reagent for C-, N-, O-, and S-Alkylations". Chemistry Letters. 8: 45-46. doi:10.1246/cl.1979.45.. ...
"Alkylation with Oxalic Esters. Scope and mechanism". Tetrahedron. 46 (17): 6113-6124. doi:10.1016/S0040-4020(01)87933-3. H. R. ...
It produces random mutations in genetic material by nucleotide substitution; particularly by guanine alkylation. This typically ...
For example, a key intermediate for the fungal hormone trisporic acid was made by its alkylation and it has been used to make ... C-3 and C-1 alkylation of Hagemann's ester (Ethyl 2-methyl-4-oxocyclohex-2-enecarboxylate) with alkyl halides and Michael ... White, James D.; Sung, Wing Lam (1974). "Alkylation of Hagemann's ester. Preparation of an intermediate for trisporic acid ...
S-alkylationEdit. Thiols, or more specific their conjugate bases, are readily alkylated to give thioethers: RSH + R′Br + B → ... Another method entails the alkylation of sodium hydrosulfide. RX + NaSH → RSH + NaX (X = Cl, Br, I). This method is used for ... alkyl halides are converted to thiols via a S-alkylation of thiourea. This multistep, one-pot process proceeds via the ... A related two-step process involves alkylation of thiosulfate to give the thiosulfonate ("Bunte salt"), followed by hydrolysis ...
Weiberth, Franz J.; Hall, Stan S. (1986). "Tandem alkylation-reduction of nitriles. Synthesis of branched primary amines". ...
... is a form of alkylation, with a methyl group replacing a hydrogen atom. These terms are commonly used in chemistry ... The term methylation in organic chemistry refers to the alkylation process used to describe the delivery of a CH3 group. ... Purdie, T.; Irvine, J. C. (1903). "C.?The alkylation of sugars". Journal of the Chemical Society, Transactions. 83: 1021-1037. ... a biophysical method to determine the methylisation state of DNA Alkylation Methoxy Titanium-zinc methylenation Petasis reagent ...
Depending on the acid used, the unit is called a sulfuric acid alkylation unit (SAAU) or hydrofluoric acid alkylation unit ( ... Lewis acids will catalyze the alkylation reaction (alkylation of isobutane with olefins was discovered using aluminium chloride ... Refineries examine whether it makes sense economically to install alkylation units. Alkylation units are complex, with ... "Alkylation Unit". McKinsey & Company. Retrieved October 16, 2019.. *^ Viswanathan, Balasubramanian (September 7, 2016). "2". ...
Alkylation, in petroleum refining, chemical process in which light, gaseous hydrocarbons are combined to produce high-octane ... Alkylation, in petroleum refining, chemical process in which light, gaseous hydrocarbons are combined to produce high-octane ... Alkylation units were installed in petroleum refineries in the 1930s, but the process became especially important during World ... molecules in the gasoline range; alkylation, a process combining an olefin and a paraffin such as isobutane; isomerization, the ...
... alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a ... C-alkylation can also be effected by alkenes in the presence of acids. N- and P-alkylation are important processes for the ... In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the ... C-alkylation is a process for the formation of carbon-carbon bonds. For alkylation at carbon, the electrophilicity of alkyl ...
Key to the alkylation of alcohols is the use of catalysts that render the hydroxyl group a good leaving group. The largest ... Amine alkylation (amino-de-halogenation) is a type of organic reaction between an alkyl halide and ammonia or an amine. The ... N-alkylation is a general and useful route to quaternary ammonium salts from tertiary amines, because overalkylation is not ... Examples of N-alkylation with alkyl halides are the syntheses of benzylaniline, 1-benzylindole, and azetidine. Another example ...
C-alkylationEdit. C-alkylation is a process for the formation of carbon-carbon bonds. For alkylation at carbon, the ... alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a ... N-and P-alkylationEdit. N- and P-alkylation are important processes for the formation of carbon-nitrogen and carbon-phosphorus ... In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the ...
DuPont is committed to alkylation research and has extensive experience in assisting refiners with alkylation research, design ... STRATCO® alkylation technology is licensed and marketed by DuPont as part of its Clean Technologies portfolio in Overland Park ... DuPont is the world leader in alkylation technology with over 90 units licensed and with more than 800,000 BPSD (31,400 kmta) ... As part of DuPonts commitment to innovation, the alkylation unit at Hengli will utilize the patented XP2 technology in the ...
The output from the first alkylation reaction zone is supplied, at least in part, to a second alkylation zone which is operated ... by the gas phase alkylation of benzene over a molecular sieve aromatic alkylation catalyst followed by liquid phase alkylation ... A feedstock containing benzene and ethylene is supplied to a first alkylation reaction zone containing a molecular sieve ... aromatic alkylation catalyst. The reaction zone is operated at temperature and pressure conditions to cause gas phase ...
A palladium-catalyzed asymmetric allylic alkylation (AAA) is used to set the spiro(pyrrolidine-oxindo... ... A palladium-catalyzed asymmetric allylic alkylation (AAA) is used to set the spiro(pyrrolidine-oxindole) stereogenic center. ...
Browse Sigma-Aldrichs Alkylation Reagents to find products in DMF-Dialkylacetals, Diazoalkales, Esterification Reagents, ... USA Home > Product Directory > Analytical/Chromatography > Analytical Reagents > Derivatization Reagents > Alkylation Reagents ...
Alkylation is a widely used technique in organic chemistry. ... Alkylation is a widely used technique in organic chemistry. ... Alkylation is the process by when an alkyl group is added to a substrate molecule. ... Alkylation is the process by when an alkyl group is added to a substrate molecule. ... Alkylation of aromatic rings via alkyl halide (Friedel-Crafts alkylation reaction). *Alkylation of alkyl halides (Suzuki cross- ...
... , Top Key Players Albemarle, BASF, CRI, Sinopec - published on ... 1 Alkylation Catalyst Market Overview. 1.1 Product Overview and Scope of Alkylation Catalyst. 1.2 Alkylation Catalyst Segment ... 1.4 Global Alkylation Catalyst Market Size. 1.4.1 Global Alkylation Catalyst Revenue (2014-2025). 1.4.2 Global Alkylation ... 1.3 Global Alkylation Catalyst Market by Region. 1.3.1 Global Alkylation Catalyst Market Size Region. 1.3.2 North America ...
Adaptive Response Sister Chromatid Exchange GM637 Cell Methyl Guanine Alkylation Damage This is a preview of subscription ... Samson L., Schwartz J.L. (1983) The Induction of Resistance to Alkylation Damage in Mammalian Cells. In: Lawrence C.W. (eds) ... Loveless, A: Possible relevance of 0-6 alkylation of deoxyguanosine to the mutagenicity and carcinogenicity of nitrosamines and ...
D8: STRATCO, The 1990 Alkylation Seminar: K. Masters, Amylene Alkylation. D9: NPRA Q&A Sessions: C5 alkylation questions (from ... In addition, under the heading alkylation pretreatment on page 3 of D7, reference is made to hydrotreating alkylation ... Alkylation pretreatment and the further chapter TAME feedstock pretreatment. Alkylation and TAME production are therefore ... T 1245/09 (Gasoline hydroisomerization/alkylation/UOP) of 20.9.2011. European Case Law Identifier:. ECLI:EP:BA:2011: ...
This Review summarizes transition-metal-catalyzed alkylations of various ... the use of unactivated olefins for alkylations has become attractive from both cost and sustainability viewpoints. ... Alkylation reactions represent an important organic transformation to form C-C bonds. In addition to conventional approaches ... According to the mode of activation, the Review is divided into two sections: alkylation via C-H activation and alkylation via ...
68512-30-1)]. The test material was a UVCB substance containing alkylation products of phenol with α-methylstyrene (mono-, di- ... The study revealed that only the Dimers and Trimers of test material (Oligomerisation and alkylation reaction products of 2- ... Name of test material (as cited in study report): Novares LA 300, Oligomerisation and alkylation reaction products of 2- ... The target substance oligomerisation and alkylation reaction products of 2-phenylpropene and phenol (OAPP) (EC no. 700-960-79) ...
Exposure controlsPersonal protective equipmentGeneral protective and hygienic measures- The usual precautionary measures should be adhered to general rules for handling chemicals.- Use skin protection cream for preventive skin protection.- Be sure to clean skin thoroughly after work and before breaks.- Take off immediately all contaminated clothing- Wash hands during breaks and at the end of the work.- Store protective clothing separately.Breathing equipment:- In case of brief exposure or low pollution use breathing filter apparatus. In case of intensive or longer exposure use breathing apparatus that is independent of circulating air.- Filter AProtection of hands:- Only use chemical-protective gloves with CE-labelling of category III (EN 374).- Heat protection gloves (in case of elevated storage- and transport temperature).Material of gloves- Nitrile rubber, NBR- Butyl rubber, BR- The selection of the suitable gloves does not only depend on the material, but also on further marks of quality and ...
Short-term toxicity of Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol (OAPP) to fish was ...
Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol Type:. legal entity composition of the substance ... Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol EC Number:. 700-960-7. Molecular formula:. not ...
... Organic Synthesis: Bifunctional catalyst weds reluctant partners by Bethany ... Dong notes that the reaction has several advantages over traditional ketone alkylations, which typically are done by ... a number of other groups have successfully demonstrated the use of olefins to perform the equivalent of enolate alkylation, ...
In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. It is a major aspect of the ... In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). ... Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl ... Selective alkylation, or adding parts to the chain with the desired functional groups, is used, especially if there is no ...
Microwave assisted N-alkylation of amine functionalized crystal-like mesoporous phenylene-silica.. Lourenço MA1, Siegel R, ... N-alkylation reaction of amine functionalized phenylene moieties in crystal-like mesoporous silica is successfully achieved ...
An easy Pd-mediated oxidation of primary amines to imines followed by aniline addition enables an alkylation of anilines. The ... Well-defined Co(II) complexes stabilized by a PCP ligand catalyze efficient alkylations of aromatic amines by primary alcohols ... The addition of 4 molecular sieves enables an efficient cobalt(II)-catalyzed N-alkylation of both aromatic and aliphatic amines ... A base-catalyzed/promoted transition-metal-free direct alkylation of amines with either aromatic or aliphatic alcohols provides ...
Isobutene/olefin alkylation is a major refinery process in which light hydrocarbons (isobutene and, mainly, C3 and C4 olefins) ... This project will develop a novel reactor approach to solid-catalyzed isobutene/olefin alkylation in which olefin ... polymerization at the catalytic surface is limited, thereby avoiding the primary issue with solid catalyzed alkylation. ...
Alkylation of the aza-enolate of valerolactim methyl ether with electrophiles affords α-alkyl lactims. Subsequent mild, acidic ... A highly enantioselective catalytic alkylation of cyanoacetates was achieved using a chiral phase-transfer catalyst to give α,α ... A photo-organocatalytic enantioselective α- and γ-alkylation of aldehydes and enals with bromomalonates occurs under ... In contrast, bis(2,2,2-trifluoroethyl) malonates readily undergo dehydrative alkylation with primary and some secondary ...
Regioselective ketone α-alkylation with simple olefins via dual activation Message Subject. (Your Name) has forwarded a page to ...
Reports emphasize developments in process technology for Alkylation for Motor Fuels that have potential implications for the ... Solid catalyst alkylation processes are being researched as a response to the potential ban of HF acid use because of ... Alkylation has become an important refinery process because of increasing demand for high octane and low vapor pressure ... The flexibility of alkylation in producing a high quality gasoline blending component is evaluated for three types of ...
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... but the functional impact of alkylation damage across proteomes is poorly understood. We used Click chemistry and shotgun ... Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, ... Alkylation damage by lipid electrophiles targets functional protein systems Mol Cell Proteomics. 2014 Mar;13(3):849-59. doi: ... Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact ...
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  • Amine alkylation (amino-de-halogenation) is a type of organic reaction between an alkyl halide and ammonia or an amine. (wikipedia.org)
  • For laboratory use, the N-alkylation reaction is often unselective. (wikipedia.org)
  • A feedstock containing benzene and ethylene is supplied to a first alkylation reaction. (google.com.au)
  • The reaction zone is operated at temperature and pressure conditions to cause gas phase ethylation of the benzene with the production of an alkylation product comprising a mixture of ethylbenzene and polyalkylated aromatic components including diethylbenzene. (google.com.au)
  • The output from the first alkylation reaction zone is supplied, at least in part, to a second alkylation zone which is operated in the liquid phase or in the supercritical region followed by supply to an intermediate recovery zone for the separation and recovery of ethylbenzene and a polyalkylated aromatic compound component including diethylbenzene. (google.com.au)
  • h) recycling benzene recovered from said recovery zone to at least one of said first and second alkylation reaction zones. (google.com.au)
  • 2. The method of claim 1 wherein substantially all of the alkylation product recovered from said first alkylation reaction zone is supplied to said second alkylation reaction zone. (google.com.au)
  • 3. The method of claim 1 wherein a first portion of said product from said first alkylation reaction zone is supplied to said second alkylation reaction zone and a second portion of said product from said first alkylation reaction zone bypasses said second alkylation reaction zone and is supplied directly to said recovery zone. (google.com.au)
  • 4. The method of claim 1 wherein the molecular sieve catalyst in said first alkylation reaction zone is a small to intermediate pore size molecular sieve and the molecular sieve catalyst in said second aromatic alkylation zone is an intermediate pore size molecular sieve having an effective pore size greater than the effective pore size of the catalyst in said first alkylation reaction zone. (google.com.au)
  • 5. The method of claim 4 wherein said catalyst in said second alkylation reaction zone is zeolite beta or zeolite La-Beta. (google.com.au)
  • 6. The method of claim 1 wherein the molecular sieve catalyst in said first alkylation reaction zone is monoclinic silicalite having a silica/alumina ratio greater than 250 and the catalyst in said second alkylation reaction zone is selected from the group consisting of zeolite Y, zeolite omega, zeolite beta, and zeolite lanthanum beta. (google.com.au)
  • In the petroleum industry, alkylation units are large chemical reaction vessels and associated technology. (mt.com)
  • Oligomerisation and alkylation reaction. (europa.eu)
  • N-alkylation reaction of amine functionalized phenylene moieties in crystal-like mesoporous silica is successfully achieved with about 87% of conversion in two reaction cycles. (nih.gov)
  • Alkylation of carbonyl compounds is a commonly used carbon-carbon bond-forming reaction. (sciencemag.org)
  • Chiller systems are used in two key areas within the alkylation process to control process temperature: the reaction zone and the refrigeration section. (hydrocarbonprocessing.com)
  • For the unsubstituted oxazolopiperidone, the alkylation with methyl chloride is predicted to afford mainly the exo product, a finding further corroborated from the analysis of the experimental outcome obtained in the reaction of the racemic oxazolopiperidone. (ub.edu)
  • Just like for acylation reactions, the most common type of alkylation is the Friedel-Crafts reaction and the typical etherification reaction is the Williamson synthesis. (silicycle.com)
  • Current industrial alkylation processes catalyze the reaction with concentrated liquid mineral acids, either hydrofluoric (HF) or sulfuric (H2SO4) acids, which pose serious safety and environmental risks. (doe.gov)
  • The latter include the use of an aqueous NaOH solution at 50% in toluene, which means that the organic solvent does not need to be in an anhydrous condition, as would be necessary for a conventional alkylation reaction [8]. (thefreedictionary.com)
  • Alkylation of alcohols involves the reaction of the alcohols with the alkyl sulphate which results in the formation of the ether. (transtutors.com)
  • By chemistry standards, the Friedel-Crafts alkylation is a venerable reaction. (acs.org)
  • The first part revolves around the metal-catalyzed asymmetric allylic alkylation reaction and how interactions within the catalyst affect the stereochemistry. (diva-portal.org)
  • Zuschriften Synthetic Methods DOI: 10.1002/ange.200504021 Direct Catalytic Intermolecular a-Allylic Alkylation of Aldehydes by Combination of Transition-Metal and Organocatalysis** Ismail Ibrahem and Armando Crdova* The a-alkylation of carbonyl compounds is a fundamental carbon-carbon bond-forming reaction in organic synthesis. (docme.ru)
  • Under standardized reaction conditions, a correlation ( R 2 = 0.88) was found between the extent of heme alkylation and in vitro antimalarial activity, suggesting that heme alkylation may be related to the mechanism of action for these trioxolanes. (asm.org)
  • The alkylation reaction was carried out in a round bottomed flask under reflux conditions and stirring at a temperature of 45 oC over a period of 5 h. (uwc.ac.za)
  • It provided a full explanation of the reaction mechanism and yielded results which supported the N3/N9 positions of alkylation over the N1/N7 sites. (up.ac.za)
  • The preference for the sites of alkylation occurs after the transition state, in which the N1/N7 reaction paths fail to proceed favourably to the end product, N1- and N7-benzyladenine, respectively. (up.ac.za)
  • This reaction resulted in the formation of nitro substituted aldehydes and ketones via an isomerization-alkylation step. (usf.edu)
  • Abstract Isobutene/olefin alkylation is a major refinery process in which light hydrocarbons (isobutene and, mainly, C3 and C4 olefins) are converted to a high octane gasoline feedstock. (sbir.gov)
  • Key to the alkylation of alcohols is the use of catalysts that render the hydroxyl group a good leaving group. (wikipedia.org)
  • In certain processes, zeolites or Lewis acids are used as alkylation catalysts. (mt.com)
  • Axens has signed an agreement with ExxonMobil Catalysts and Licensing (ExxonMobil) to sublicense the latter's sulfuric acid alkylation technology. (chemicals-technology.com)
  • The key to the technology is Ex Sact, a revolutionary solid acid catalyst engineered to overcome rapid deactivation limitations of solid-acid catalysts and provide superior alkylation performance. (process-worldwide.com)
  • In palladium-catalyzed alkylations of allylic acetates with malonate as nucleophile, catalysts with oxazoline ligands bearing hydroxymethyl substituents in 4-position have been shown by density functional theory computations to undergo a conformational change on nucleophilic attack, which is accompanied by reduction of Pd(II) to Pd(0). (diva-portal.org)
  • However, our initial attempts into the intermolecular aalkylation of aldehydes and cyclohexanone failed and the N-alkylation of the pyrrolidine and proline catalysts occurred. (docme.ru)
  • The difficulty in applying alternative solid alkylation catalysts is related to deactivation by coking. (teknoscienze.com)
  • The research focused on the synthesis, characterisation and activity of zeolite supported metal catalysts for the Friedel-Crafts alkylation of benzene with t-butyl chloride. (uwc.ac.za)
  • The prepared catalysts were tested for the alkylation of benzene with t-butyl chloride. (uwc.ac.za)
  • Refinery catalysts are widely utilized in refining processes such as fluid catalytic cracking, alkylation, and hydrotreating. (asdreports.com)
  • In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. (wikipedia.org)
  • The alkylation process produces alkylate from propylene, butylene, and isobutane (i.e. alkylating olefins to form longer branched-chain hydrocarbons). (mt.com)
  • In addition to conventional approaches with alkyl halides or sulfonates as alkylating agents, the use of unactivated olefins for alkylations has become attractive from both cost and sustainability viewpoints. (rti.org)
  • This Review summarizes transition-metal-catalyzed alkylations of various carbon-hydrogen bonds (addition of C-H bonds across olefins) using regular olefins or 1,3-dienes up to May 2016. (rti.org)
  • The flexibility of alkylation in producing a high quality gasoline blending component is evaluated for three types of alkylation unit feedstocks: FCC butenes (the most common feedstock worldwide), FCC propylene and butenes mix (a less prevalent feedstock, particularly outside the United States), and MTBE raffinate/FCC C5 olefins (a feedstock that will become more common in the United States). (ihs.com)
  • Here, we describe development of a ketone-alkylation strategy using simple olefins as the alkylating agents. (sciencemag.org)
  • The STRATCO ® alkylation unit at Sinopec Qilu Petrochemical Corporation (Sinopec Qilu) is designed to produce 400 kmta (10,300 BPSD) of alkylate product from a MTBE raffinate feedstock and enables production of low-sulfur, high-octane, low-Rvp alkylate with zero olefins that meets the criteria of the China V standard. (hydrocarbonprocessing.com)
  • The STRATCO ® alkylation technology is a sulfuric acid-catalyzed process that converts low-value, straight-chain olefins (propylene, butylene and amylene) into high-value, branched components called alkylate. (hydrocarbonprocessing.com)
  • The STRATCO ® alkylation technology helps refiners safely produce cleaner-burning gasoline with high octane, low Reid vapor pressure, low sulfur, zero aromatics and zero olefins. (hydrocarbonprocessing.com)
  • Alkylation of Isobutane with C.sub.4 Olefins", 27 Ind. (patentgenius.com)
  • In the petrochemical industry, the current state-of-the-art of zeolite-catalyzed aromatic alkylation process involves olefins as an alkylating agent, which is still mostly derived from fossil fuels. (europa.eu)
  • Unlike traditional refinery alkylation technologies that utilize strong acids K-SAAT produces alkylates by combining light olefins and isobutane using a solid catalyst that is intrinsically safer and more environmentally benign. (process-worldwide.com)
  • While FCCUs are a very common unit in modern oil refineries, it is not common for a refinery to have an alkylation unit. (wikipedia.org)
  • DuPont Clean Technologies (DuPont) is pleased to announce that Hengli Petrochemical Company (Hengli), based in Dalian, China, has awarded DuPont a contract to supply the alkylation and spent acid regeneration (SAR) technologies for the new, grassroots refinery in the Changxing Island Harbor Industrial Zone. (prweb.com)
  • The grassroots refinery complex, with the addition of STRATCO® alkylation technology, will allow Hengli to produce a high quality alkylate product (used as a blending component in the gasoline pool) from a 100% isobutylene feed stream. (prweb.com)
  • DuPont is pleased to provide Hengli Petrochemical with our world-class sulfuric acid alkylation technology to improve the overall gasoline pool from the refinery," said Kevin Bockwinkel, global business manager for the STRATCO® Alkylation Technology. (prweb.com)
  • In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). (wikidoc.org)
  • Alkylation has become an important refinery process because of increasing demand for high octane and low vapor pressure gasoline blending components. (ihs.com)
  • DuPont Clean Technologies (DuPont) is pleased to announce that the STRATCO ® alkylation unit at the Sinopec Qilu refinery in Zibo, Shandong Province, China, successfully completed the performance test, certifying that the unit is meeting required performance guarantees. (hydrocarbonprocessing.com)
  • An East Coast refinery test was conducted by Aggreko's Process Services (APS) group and the DuPont Clean Technologies division where chiller systems were installed in the reactor feed section of the STRATCO alkylation unit. (hydrocarbonprocessing.com)
  • The UNB team included Jeremy Hughes, Bruce Scott, Erin Flanagan and Cody Brown, whose project, "The Use of Solid Catalyst Technology in the Alkylation of Refinery Grade Propylene," was sponsored by Irving Oil Ltd. (thefreedictionary.com)
  • Now we produce two million liters of 100 LL gasoline per day in alkylation unit of Aban oil refinery, which is a strategic product and is used as fuel by planes and helicopters' Qasemi noted. (thefreedictionary.com)
  • The firm will also have the opportunity to use the technology to revamp the existing hydrofluoric acid alkylation unit at the Wynnewood refinery. (process-worldwide.com)
  • KBR has entered into a contract with Wynnewood Refining Company for engineering and design services relating to KBR's Solid Acid Alkylation Technology for Wynnewood's refinery located in Oklahoma, USA. (process-worldwide.com)
  • Under the terms of the contract, KBR will provide basic engineering and design services for its K-SAAT technology and the opportunity to utilise the technology to revamp the existing hydrofluoric acid alkylation unit at the Wynnewood refinery. (process-worldwide.com)
  • The case explored in this paper, cleaner production approaches to reduce fluorine use and waste in the alkylation process at a specific UK oil refinery, illustrates the need to broaden the issues and trade-offs considered in assessing processing and waste management options. (thefreedictionary.com)
  • DuPont STRATCO Refinery Solutions, "HF Alkylation Course," (2006). (thefreedictionary.com)
  • Industry often relies on green chemistry methods involving alkylation of amines with alcohols, the byproduct being water. (wikipedia.org)
  • P h − O − + M e 2 − S O 4 ⟶ P h − O − M e + M e − S O 4 − {\displaystyle \mathrm {Ph{-}O^{-}\ +\ Me_{2}{-}SO_{4}\ \longrightarrow \ Ph{-}O{-}Me\ +\ Me{-}SO_{4}^{-}} } (with Na+ as a spectator ion) More complex alkylation of a alcohols and phenols involve ethoxylation. (wikipedia.org)
  • Industrially, most alkylations are typically conducted using alcohols, not alkyl halides. (wikipedia.org)
  • Alcohols are less expensive than alkyl halides and their alkylation does not produce salts, the disposal of which can be problematic. (wikipedia.org)
  • More complex alkylation of a alcohols and phenols involve ethoxylation . (wikipedia.org)
  • Alkylating agents are typically olefin, alcohols, sulfates halides and various nitrogen containing compounds that promote alkylation by enabling alkyl groups to selectively bond to molecules. (mt.com)
  • Well-defined Co(II) complexes stabilized by a PCP ligand catalyze efficient alkylations of aromatic amines by primary alcohols into mono- N -alkylated amines in very good yields. (organic-chemistry.org)
  • A base-catalyzed/promoted transition-metal-free direct alkylation of amines with either aromatic or aliphatic alcohols provides the desired amines in good yields. (organic-chemistry.org)
  • The addition of 4 molecular sieves enables an efficient cobalt(II)-catalyzed N-alkylation of both aromatic and aliphatic amines with alcohols with high chemoselectivity (amines vs imines). (organic-chemistry.org)
  • In contrast, bis(2,2,2-trifluoroethyl) malonates readily undergo dehydrative alkylation with primary and some secondary alcohols. (organic-chemistry.org)
  • We present a method for N-alkylation of unprotected amino acids with alcohols with excellent yield and stereochemistry retention. (sciencemag.org)
  • Such competitive adsorption effects can be expected in Friedel-Crafts-type alkylation reactions with zeolites, because molecules of completely different physiochemical nature are involved (i.e., aromatic substrate and alkylating agents such as alcohols, esters, anhydrides, etc. (thefreedictionary.com)
  • Alkylation of para-Cresol With Lower Alcohols Ove. (brillonline.com)
  • What is Alkylation Of Alcohols? (transtutors.com)
  • Transtutors is the best place to get answers to all your doubts regarding alkylation of alcohols with examples . (transtutors.com)
  • The third type is the selective mono-N-alkylation of amines with alcohols. (diva-portal.org)
  • 8] Most recently, transition-metal catalysis was employed in the a-alkylation of ketone enolates with alcohols. (docme.ru)
  • H2SO4-catalysed isobutane alkylation with alkenes is an important industrial process used to obtain high-octane alkylate. (doaj.org)
  • Karasev, "Acid Soluble Oil, by Product Formed in Isobutane Alkylation with Alkene in the Presence of Trifluoro Methane Sulfonic Acid. (thefreedictionary.com)
  • Alkylation of isobutane with butenes is one of the most important processes making high octane number gasoline. (teknoscienze.com)
  • Detailed simulations for reactive distillation in a zeolite catalysed alkylation of isobutane with butane were conducted. (teknoscienze.com)
  • Alkylation of isobutane with butenes can be considered as one of the most important processing for obtaining high octane number gasoline. (teknoscienze.com)
  • Power generation and HVAC specialty rental company, Aggreko, and sulfuric acid alkylation technology licensor, DuPont, have teamed up to provide Aggreko temperature control, including chiller systems, to DuPont STRATCO sulfuric acid alkylation customers worldwide. (hydrocarbonprocessing.com)
  • Alkylation , in petroleum refining , chemical process in which light, gaseous hydrocarbons are combined to produce high-octane components of gasoline . (britannica.com)
  • Alkylation units were installed in petroleum refineries in the 1930s, but the process became especially important during World War II , when there was a great demand for aviation gasoline. (britannica.com)
  • For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. (wikipedia.org)
  • The unique feed stream (100-percent isobutylene) available from the Hengli Petrochemical facility marks the beginning of a new era for alkylation in the gasoline market as the butane-to-alkylate movement grows around the world. (prweb.com)
  • In the manufacturing of gasoline , alkylation is used to produce high octane product by converting isoparaffins and low-molecular-weight alkenes into alkylate. (mt.com)
  • Alkylation is used by the petroleum refining industry to produce a low-vapor-pressure, high-octane gasoline blendstock. (doe.gov)
  • The major project involves the installation of a Vacumm Distillation Unit, Light Olefine Alkylation Unit, Light Gasoline Isomerization Unit, Gasoline Mixing Unit and Utility System. (thefreedictionary.com)
  • The alkylation value for propylene in motor gasoline remains over $0.75/lb. (thefreedictionary.com)
  • Here you can see the latest Iron Hydride Radical Reductive Alkylation Unactivated Alkenes articles that have been published worldwide. (bioportfolio.com)
  • We have published hundreds of Iron Hydride Radical Reductive Alkylation Unactivated Alkenes news stories on BioPortfolio along with dozens of Iron Hydride Radical Reductive Alkylation Unactivated Alkenes Clinical Trials and PubMed Articles about Iron Hydride Radical Reductive Alkylation Unactivated Alkenes for you to read. (bioportfolio.com)
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  • Iron Hydride Radical Reductive Alkylation of Unactivated Alkenes. (bioportfolio.com)
  • The process involves a new strategic bond disconnection resulting in the reductive alkylation of nonactivated alkenes. (bioportfolio.com)
  • Reductive alkylation in which Schiff's bases formed between an aldehyde and an amino group may be reduced with sodium borohydride (NaBH 4 ) or sodium cyanoborohydride is a convenient and gentle method to specifically introduce alkyl groups into proteins at ε-amino groups of lysine (1-4). (springer.com)
  • Royer G.P., Liberatore F.A. (1978) Immobilization of Enzymes by Reductive Alkylation. (springer.com)
  • C-alkylation can also be effected by alkenes in the presence of acids. (wikipedia.org)
  • A palladium-catalyzed asymmetric allylic alkylation (AAA) is used to set the spiro(pyrrolidine-oxindole) stereogenic center. (mendeley.com)
  • An enantioselective synthesis of allenes through palladium-catalyzed asymmetric allylic alkylation using a chiral diaminophosphine oxide is described. (wiley.com)
  • The asymmetric allylic alkylations proceeded in the presence of a catalytic amount of lithium acetate at 4 °C, affording the chiral allenes in excellent yield with up to 99% ee . (wiley.com)
  • Asymmetric Synthesis of -Alkyl--aminocarboxylic Acids by Alkylation of 1-chiral-Substituted 2-Imidazolin-5-ones. (docme.ru)
  • C 0 M MU N I CAT1 0 N S Asymmetric Synthesis of a-Alkyl-a-aminocarboxylic Acids by Alkylation of 1-chiral-Substituted 2-Imidazolin-lones['l By Ulrich Schollkopf, Hans Heinrich Hausberg, Inga Hoppe, Marcos Segal, and U d o Reiterr] Owing to the immensely important role played by optically active amino acids in pure and applied chemistry, asymmetric amino acid synthesis has attracted especial interest. (docme.ru)
  • An alkylation reactor uses ExxonMobil catalyst to convert benzene and propylene to cumene in the liquid phase. (exxonmobilchemical.com)
  • Refineries use the alkylation process to convert low value mixed butylene, propylene and/or amylene feed streams into a high value alkylate product. (hydrocarbonprocessing.com)
  • Benzene alkylation with propylene was studied in the gas phase using a catalytic membrane reactor and a fixed-bed reactor in the temperature range of 200-300 °C and with a weight hourly space velocity (WHSV) of 51 h −1 . (mdpi.com)
  • Torres-Rodríguez M, Gutiérrez-Arzaluz M, Mugica-Álvarez V, Aguilar-Pliego J, Pergher S. Alkylation of Benzene with Propylene in a Flow-Through Membrane Reactor and Fixed-Bed Reactor: Preliminary Results. (mdpi.com)
  • A process for the production of ethylbenzene by the gas phase alkylation of benzene over a molecular sieve aromatic alkylation catalyst followed by liquid phase alkylation of the product of the gas phase alkylation. (google.com.au)
  • In this report, the global Benzene Alkylation Catalyst market is valued at USD XX million in 2016 and is expected to reach USD XX million by the end of 2022, growing at a CAGR of XX% between 2016 and 2022. (reportsnreports.com)
  • It was also found that the Mn was not active in the alkylation of benzene as shown by the inactivity of the 10%MnM, where 10% by weight Mn was loaded on MCM-41. (uwc.ac.za)
  • The alkylation of phenols is particularly straightforward since it is subject to fewer competing reactions. (wikipedia.org)
  • In organic chemistry , alkylation reactions are common. (mt.com)
  • One of the frequently employed alkylation reactions is the Friedel-Crafts . (mt.com)
  • Alkylation reactions may be either nucleophilic or electrophilic, and occur by addition or substitution. (mt.com)
  • The petroleum industry relies on alkylation reactions as starting points for modern consumer products. (mt.com)
  • In the present work, the formation reactions of undesired substances were used in the description of the alkylation process, indicating the sensitivity of the prediction to H2SO4 activity variations. (doaj.org)
  • Alkylation reactions represent an important organic transformation to form C-C bonds. (rti.org)
  • Alkylation reactions are the transfer of an alkyl group from one molecule to the other via alkylating agents, that may have an electrophilic or nucleophilic character. (silicycle.com)
  • They're not very electrophilic, and because the Friedel-Crafts alkylation involves generating a carbocation intermediate, you get a lot of competing side reactions and rearrangements," she says. (acs.org)
  • In this context, the catalytic direct a-alkylation of nonstabilized aldehydes and ketones is challenging due to competing side reactions, such as aldol condensations, Cannizzaro and Tishchenko reactions, and N- or O-alkylations. (docme.ru)
  • 13] Well-designed, two-component activation systems with Pd that combine metal catalysis and the employment of stoichiometric or catalytic amounts of an organic catalyst have also been successfully employed in allylic alkylation reactions. (docme.ru)
  • Therefore, for laboratory purposes, N-alkylation is often limited to the synthesis of tertiary amines. (wikipedia.org)
  • A one-pot procedure for the synthesis of 2-alkyl-2-arylcyanoacetates based on a Pd(OAc) 2 /dppf-catalyzed enolate arylation followed by in situ alkylation tolerates a diverse range of aryl and heteroaryl bromides, and provides a rapid entry to a wide range of products in very good to yield. (organic-chemistry.org)
  • It is sufficiently basic to deprotonate moderately acidic hydrogens, as in the alkylation of amines and phenols (Williamson ether synthesis) and the esterification of carboxylic acids using alkyl halides. (silicycle.com)
  • Anomeric O-alkylation/arylation is applied to the synthesis of 2-deoxy-β-glycosides. (harvard.edu)
  • In the same report, another general strategy from the synthesis of ispinesib followed was N- alkylation of amino acid prior to the formation of quinazolinone nucleus (Scheme 3). (thefreedictionary.com)
  • Selective alpha-C-H activation results in the synthesis of the first bridging metallaaziridine complex for the catalytic alpha-alkylation of primary amines. (ubc.ca)
  • Khan, Pasha Moeenuddin, "Application of Pd catalyzed alkylation: Synthesis of bicyclic furans, isoxazolines and new cyclopentane amino acid analogs" (2008). (usf.edu)
  • R4} _{{quaternay \atop ammonium} \atop cation}+\underbrace {X^{-}} _{halide \atop anion}} _{quaternay\ ammonium\ salt}}}} Amines and ammonia are generally sufficiently nucleophilic to undergo direct alkylation, often under mild conditions. (wikipedia.org)
  • Depending on the acid used, the unit is called a sulfuric acid alkylation unit (SAAU) or hydrofluoric acid alkylation unit (HFAU). (wikipedia.org)
  • For example, most methyl amines are prepared by alkylation of ammonia with methanol. (wikipedia.org)
  • The contract includes the license and engineering design packages for the STRATCO® alkylation and MECS® SAR units. (prweb.com)
  • As part of DuPont's commitment to innovation, the alkylation unit at Hengli will utilize the patented XP2 technology in the STRATCO® Contactor™ reactor. (prweb.com)
  • STRATCO® alkylation technology is licensed and marketed by DuPont as part of its Clean Technologies portfolio in Overland Park, Kansas. (prweb.com)
  • As Sinopec continues to drive towards lower emission specifications, DuPont was excited to assist with a custom-designed solution," said Kevin Bockwinkel, global business manager, STRATCO ® alkylation technology. (hydrocarbonprocessing.com)
  • Fundamentally the same as commercially operating reactors in service throughout the world, the Model 74 Contactor™ reactors reduce the total number of reactors and plot space required for STRATCO ® alkylation units and result in an overall lower capital cost. (hydrocarbonprocessing.com)
  • These reactors continue to offer the high reliability and productivity refiners have grown accustomed to with the STRATCO ® alkylation technology. (hydrocarbonprocessing.com)
  • Licensed and marketed by DuPont as part of its Clean Technologies portfolio, the STRATCO ® alkylation technology is the world-leading alkylation technology with more than 100 licensed units worldwide and more than 915,000 bpsd (35,800 kmta) of installed capacity. (hydrocarbonprocessing.com)
  • Derivatize carboxyl acids, phenols, and sulfonamides for electron-capture detection (ECD) GC analysis with the Thermo Scientific™ Pentafluorobenzyl Bromide (PFBBr) Alkylation Reagent. (thermofisher.com)
  • The rate of alkylation follows the order tertiary amine (wikipedia.org)
  • Microwave assisted N-alkylation of amine functionalized crystal-like mesoporous phenylene-silica. (nih.gov)
  • a) O xidation with Jones Reagent (Aldehydes) b) Bayer-Villiger o xidation (Ketones) b) En amine formation 4. (coursehero.com)
  • For alkylation at carbon, the electrophilicity of alkyl halides is enhanced by the presence of a Lewis acid such as aluminium trichloride. (wikipedia.org)
  • Examples of N-alkylation with alkyl halides are the syntheses of benzylaniline, 1-benzylindole, and azetidine. (wikipedia.org)
  • Secondary alkyl halides can be tricky to prepare in the lab because the intermediates en route to making them tend to rearrange. (acs.org)
  • The same can be said for using secondary alkyl halides as reactants in the Friedel-Crafts alkylation. (acs.org)
  • 1] The conventional a-alkylation of carbonyl compounds is performed by utilizing stoichiometric amounts of metal enolates for addition to alkyl halides. (docme.ru)
  • This report covers the technology and economics of sulfuric acid and hydrofluoric acid processes and a hypothetical solid catalyst alkylation process. (ihs.com)
  • Solid catalyst alkylation processes are being researched as a response to the potential ban of HF acid use because of increasing concern in the United States (especially the Los Angeles basin) about the potential environmental and safety risks. (ihs.com)
  • We evaluate the technology and economics associated with the likely characteristics of a solid catalyst alkylation process. (ihs.com)
  • The goal was to develop an economical solid catalyst alkylation process via supercritical fluid (SCF) regeneration. (doe.gov)
  • This project is designed to develop an economical solid catalyst alkylation process via SCF regeneration. (doe.gov)
  • This project developed an economical solid catalyst alkylation process via SCF regeneration. (doe.gov)
  • Tailleur, "Simulation of a Spouted Bed Reactor for Solid Catalyst Alkylation ," Fuel 86, 1313-1324 (2007). (thefreedictionary.com)
  • Methylation is the most common type of alkylation, being associated with the transfer of a methyl group . (wikidoc.org)
  • An alkylation unit (alky) is one of the conversion processes used in petroleum refineries . (wikipedia.org)
  • N- and P-alkylation are important processes for the formation of carbon-nitrogen and carbon-phosphorus bonds. (wikipedia.org)
  • One way to improve and predict unsteady alkylation processes is to develop a mathematical model that considers catalyst deactivation. (doaj.org)
  • Typical catalyst regeneration processes are oxidative and destroy significant levels of acidic alkylation catalyst activity. (doe.gov)
  • However, the conventional enolate alkylation approach remains problematic due to lack of regioselectivity, risk of overalkylation, and the need for strongly basic conditions and expensive alkyl halide reagents. (sciencemag.org)
  • Alkylating agents use selective alkylation by adding the desired aliphatic carbon chain to the previously chosen starting molecule. (wikipedia.org)
  • Selective alkylation, or adding parts to the chain with the desired functional groups, is used, especially if there is no commonly available biological precursor. (wikidoc.org)
  • Alkylation of 2-oxygenated diphenylmethane derivatives using sec-butyllithium and (−)-sparteine gave enantiomeric excesses of up to 60% with allyl bromide but alkylations with methyl electrophiles were poorly selective. (salford.ac.uk)
  • This project will develop a novel reactor approach to solid-catalyzed isobutene/olefin alkylation in which olefin polymerization at the catalytic surface is limited, thereby avoiding the primary issue with solid catalyzed alkylation. (sbir.gov)
  • The invention provides a substantially fail-safe HF alkylation process and reactor apparatus. (patentgenius.com)
  • L, "Fixed-Bed Alkylation Using SLP-Type Catalyst in a Chromatographic-Type Reactor Concept," Ind. (thefreedictionary.com)
  • The Kumada coupling employs both a nucleophilic alkylation step subsequent to the oxidative addition of the aryl halide (L = Ligand , Ar = Aryl ). (wikipedia.org)
  • However the adoption of zeolites on large scale Friedel-Crafts alkylation has been hampered by the high cost of zeolite production from commercial sources. (uwc.ac.za)
  • Your search returned 2 alkB, alkylation repair homolog 1 (E. coli) Biomolecules across 2 suppliers. (biocompare.com)
  • Direct Catalytic Intermolecular -Allylic Alkylation of Aldehydes by Combination of Transition-Metal and Organocatalysis. (docme.ru)
  • For example, Tamaru and co-workers reported that the a-allylic alkylation of aldehydes is possible in the presence of a catalytic amount of palladium and a slight excess of Et3B. (docme.ru)
  • The main emphasis of this work is to utilize Pd catalyzed allylic alkylation to synthesize new heterocycles including furans, isoxazolines and new cyclopentane amino-acid analogs in an enantioselective manner. (usf.edu)
  • Chapter 3 describes Pd(0) catalyzed allylic alkylation of allylic esters using various 1°, 2° nitroalkanes. (usf.edu)
  • Site-specific alkylation of DNA could be a useful tool for regulating gene expression. (caltech.edu)
  • Nicholas R Wurtz, Peter B Dervan, Sequence specific alkylation of DNA by hairpin pyrrole-imidazole polyamide conjugates, Chemistry & Biology, Volume 7, Issue 3, 1 March 2000, Pages 153-161, ISSN 1074-5521, http://dx.doi.org/10.1016/S1074-5521(00)00085-5. (caltech.edu)
  • In general, pretreatment with these modifiers of liver monooxygenase resulted in a decrease in specific alkylation of DNA and in the ratio of 7-methylguanine to guanine. (aacrjournals.org)
  • A highly enantioselective catalytic alkylation of cyanoacetates was achieved using a chiral phase-transfer catalyst to give α,α-disubstituted α-cyanoacetates which have a chiral quaternary carbon. (organic-chemistry.org)
  • This results in high levels of catalyst consumption, making solid catalytic alkylation economically and environmentally unacceptable. (doe.gov)
  • For The process of alkylation, see Alkylation . (wikipedia.org)
  • C-alkylation is a process for the formation of carbon-carbon bonds. (wikipedia.org)
  • Alkylation is a chemical process by which an alkyl group is attached to an organic substrate molecule via addition or substitution. (mt.com)
  • In order for alkylate to be used as a high-volume, ultraclean fuel, an alternative safe and environmentally acceptable alkylation process is required. (doe.gov)
  • Currently the only proven alternative is sulphuric acid (see Existing Alkylation Process and Waste Management Section) and the trade-offs are such that there is no general preference for one process over the other (Chapin et al. (thefreedictionary.com)
  • There are a few methods for the catalytic intermolecular a-alkylation of nonactivated aldehydes and ketones. (docme.ru)
  • However, when the angular carbon adopts an S configuration, the preference for the exo alkylation stems from the intermolecular steric hindrance between the enolate and the alkylating reagent. (ub.edu)
  • Amino acids carrying aromatic carbo- and heterocycles in the side chain, such as naphthyl-, biphenyl- and pyridylalanines, have been prepared by alkylation of a glycine enolate with a haloalkyl carbocycle or heterocycle, with enantiomeric excess up to 87% using the ephedrine amide protocol. (open.ac.uk)
  • For alkylation, sulphuric acid containing 88%-98% monohydrate is typically used. (doaj.org)
  • Catalyst production is treated as part of the Background because both HF and sulphuric acid are bulk commodities so that any change in use for this alkylation plant would represent no more than a marginal change in demand. (thefreedictionary.com)
  • N-methyl-N-nitrosourea (MeNu), on the other hand, causes the alkylation of mainly guanine residues. (portlandpress.com)
  • Alkylation of deoxyribonucleic acid in vivo in various organs of C57BL mice by the carcinogens N -methyl- N -nitrosourea, N -ethyl- N -nitrosourea and ethyl methanesulphonate in relation to induction of thymic lymphoma. (portlandpress.com)
  • An easy Pd-mediated oxidation of primary amines to imines followed by aniline addition enables an alkylation of anilines. (organic-chemistry.org)
  • Alkylation will readily form carbon bonds between nitrogen, phosphorus, oxygen and sulfur atoms in organic compounds. (mt.com)
  • Rocha Gonsalves, " Chiral Pyrrolidine-Based Salen Ligands for the Enantioselective Alkylation of Aromatic Aldehydes", Letters in Organic Chemistry (2007) 4: 80. (eurekaselect.com)
  • The alkylation of phenol derivatives can be achieved in good yield via Lewis or Brønsted acid. (rsc.org)
  • The feasibility of distilling alkylation product and technical alkyl phenol in a continuous apparatus was established. (dtic.mil)
  • The conditions for distilling the alkylation product and technical alkyl phenol was determined. (dtic.mil)
  • It is an effective catalyst for Friedel-Crafts alkylations and acylations. (silicycle.com)
  • From a global perspective, this report represents overall Alkylation Catalyst market size by analyzing historical data and future prospect. (openpr.com)
  • According to the mode of activation, the Review is divided into two sections: alkylation via C-H activation and alkylation via olefin activation. (rti.org)
  • As this alkylation method is not widely applied for the preparation of aza-amino acid precursors it required optimization. (thefreedictionary.com)
  • A photo-organocatalytic enantioselective α- and γ-alkylation of aldehydes and enals with bromomalonates occurs under illumination by a fluorescent light bulb in the presence of a commercially available aminocatalyst without any external photoredox catalyst. (organic-chemistry.org)
  • A new type of Salen ligands derived from (2R, 3R)-N-benzyl-2,3-diaminopyrrolidine and aromatic hydroxyaldehydes was synthesized and tested in the enantioselective alkylation of aromatic aldehydes with diethylzinc, moderate selectivity being observed. (eurekaselect.com)
  • Filter AProtection of hands:- Only use chemical-protective gloves with CE-labelling of category III (EN 374). (europa.eu)
  • Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact of alkylation damage across proteomes is poorly understood. (nih.gov)
  • Boston-based Badger Licensing LLC is a joint venture between the Badger Technology Holdings, an affiliate of Technip, and Alkylation Licensing, an affiliate of ExxonMobil Chemical Company. (thefreedictionary.com)
  • We have earlier reported that alkylation of DNA by the chemical carcinogen dimethyl sulphate, which mainly alkylates N-7 of guanine and N-3 of adenine, causes the formation of partially denatured regions in double-stranded DNA (Rizvi RY, Alvi NK & Hadi SM, Biosci. (portlandpress.com)
  • Lewis acids are particularly suited for C-alkylation. (wikipedia.org)
  • I want to get the latest chemistry news from C&EN in my inbox every week. (acs.org)
  • Transtutors has a vast panel of experienced chemistry tutors who specialize in alkylation of alcohol and can explain the different concepts to you effectively. (transtutors.com)
  • The N-alkylation of amines constitutes one of the most widely applied transformations in synthetic chemistry, but established methods often utilise non-renewable feedstocks and must be adapted for a post fossil fuel world. (manchester.ac.uk)
  • Moreover, an alkylation-resistant phenotype was observed in vivo using the BM micronucleus assay as a measure of chromosome damage. (aacrjournals.org)
  • Flow cytometry indicated that in vivo alkylation resistance in Aag null BM cells may be restricted to cells of the myeloid lineage. (aacrjournals.org)
  • Our results uncover an in vivo role for ALKBH7 in mediating a sexually dimorphic tissue response to alkylation damage that could influence individual responses to chemotherapies based upon alkylating agents. (pubmedcentralcanada.ca)
  • DuPont is the world leader in alkylation technology with over 90 units licensed and with more than 800,000 BPSD (31,400 kmta) of installed capacity. (prweb.com)
  • The successful test led to an arrangement between Aggreko and DuPont to further explore and expand temperature control for the sulfuric acid alkylation market. (hydrocarbonprocessing.com)
  • S-Alkylation of Thioacridone Derivatives Using Solid-Liquid Phase Transfer Catalysis without Solvent. (ad-astra.ro)
  • Significantly less heme alkylation was observed for the clinically utilized artemisinin derivatives compared to the equipotent trioxolanes included in this study. (asm.org)