Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)
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.
The creation of an amine. It can be produced by the addition of an amino group to an organic compound or reduction of a nitro group.
Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Alicyclic hydrocarbons in which three or more of the carbon atoms in each molecule are united in a ring structure and each of the ring carbon atoms is joined to two hydrogen atoms or alkyl groups. The simplest members are cyclopropane (C3H6), cyclobutane (C4H8), cyclohexane (C6H12), and derivatives of these such as methylcyclohexane (C6H11CH3). (From Sax, et al., Hawley's Condensed Chemical Dictionary, 11th ed)
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)
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
The generic name for the group of aliphatic hydrocarbons Cn-H2n+2. They are denoted by the suffix -ane. (Grant & Hackh's Chemical Dictionary, 5th ed)
Rhodium. A hard and rare metal of the platinum group, atomic number 45, atomic weight 102.905, symbol Rh. (Dorland, 28th ed)
Hydrocarbons with at least one triple bond in the linear portion, of the general formula Cn-H2n-2.
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.
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.
Isomeric forms and derivatives of PROPANOL (C3H7OH).
A large group of aerobic bacteria which show up as pink (negative) when treated by the gram-staining method. This is because the cell walls of gram-negative bacteria are low in peptidoglycan and thus have low affinity for violet stain and high affinity for the pink dye safranine.
Inorganic or organic compounds derived from phosphine (PH3) by the replacement of H atoms. (From Grant & Hackh's Chemical Dictionary, 5th ed)
The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Organic compounds composed exclusively of carbon and hydrogen forming a closed ring that may be either alicyclic or aromatic.
Oxidases that specifically introduce DIOXYGEN-derived oxygen atoms into a variety of organic molecules.
A trace element with the atomic symbol B, atomic number 5, and atomic weight [10.806; 10.821]. Boron-10, an isotope of boron, is used as a neutron absorber in BORON NEUTRON CAPTURE THERAPY.
Methods used for the chemical synthesis of compounds. Included under this heading are laboratory methods used to synthesize a variety of chemicals and drugs.
Alkyl compounds containing a hydroxyl group. They are classified according to relation of the carbon atom: primary alcohols, R-CH2OH; secondary alcohols, R2-CHOH; tertiary alcohols, R3-COH. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Covalent attachment of HALOGENS to other compounds.
Synthetic organic reactions that use reactions between unsaturated molecules to form cyclical products.
The collective name for the boron hydrides, which are analogous to the alkanes and silanes. Numerous boranes are known. Some have high calorific values and are used in high-energy fuels. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Organic compounds composed exclusively of carbon and hydrogen where no carbon atoms join to form a ring structure.
The reaction of two molecular entities via oxidation usually catalyzed by a transition metal compound and involving dioxygen as the oxidant.
A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)
A genus of gram-negative, aerobic, rod-shaped bacteria found in wet soil containing decaying organic material and in water. Cells tend to be pleomorphic if grown on media containing succinate or coccoid if grown in the presence of an alcohol as the sole carbon source. (From Bergey's Manual of Determinative Bacteriology, 9th ed)

Phase I and pharmacokinetic study of the topoisomerase II catalytic inhibitor fostriecin. (1/970)

We conducted a phase I and pharmacokinetic study of the topoisomerase II catalytic inhibitor fostriecin. Fostriecin was administered intravenously over 60 min on days 1-5 at 4-week intervals. Dose was escalated from 2 mg m(-2) day(-1) to 20 mg m(-2) day(-1) in 20 patients. Drug pharmacokinetics was analysed with high performance liquid chromatography with UV-detection. Plasma collected during drug administration was tested in vitro for growth inhibition of a teniposide-resistant small-cell lung cancer (SCLC) cell line. The predominant toxicities were elevated liver transaminases (maximum common toxicity criteria (CTC) grade 4) and serum creatinine (maximum CTC grade 2). These showed only a limited increase with increasing doses, often recovered during drug administration and were fully reversible. Duration of elevated alanine-amino transferase (ALT) was dose-limiting in one patient at 20 mg m(-2). Other frequent toxicities were grade 1-2 nausea/vomiting, fever and mild fatigue. Mean fostriecin plasma half-life was 0.36 h (initial; 95% CI, 0-0.76 h) and 1.51 h (terminal; 95% CI, 0.41-2.61 h). A metabolite, most probably dephosphorylated fostriecin, was detected in plasma and urine. No tumour responses were observed, but the plasma concentrations reached in the patients were insufficient to induce significant growth inhibition in vitro. The maximum tolerated dose (MTD) has not been reached, because drug supply was stopped at the 20 mg m(-2) dose level. However, further escalation seems possible and is warranted to achieve potentially effective drug levels. Fostriecin has a short plasma half-life and longer duration of infusion should be considered.  (+info)

RESPONSIVE-TO-ANTAGONIST1, a Menkes/Wilson disease-related copper transporter, is required for ethylene signaling in Arabidopsis. (2/970)

Ethylene is an important regulator of plant growth. We identified an Arabidopsis mutant, responsive-to-antagonist1 (ran1), that shows ethylene phenotypes in response to treatment with trans-cyclooctene, a potent receptor antagonist. Genetic epistasis studies revealed an early requirement for RAN1 in the ethylene pathway. RAN1 was cloned and found to encode a protein with similarity to copper-transporting P-type ATPases, including the human Menkes/Wilson proteins and yeast Ccc2p. Expression of RAN1 complemented the defects of a ccc2delta mutant, demonstrating its function as a copper transporter. Transgenic CaMV 35S::RAN1 plants showed constitutive expression of ethylene responses, due to cosuppression of RAN1. These results provide an in planta demonstration that ethylene signaling requires copper and reveal that RAN1 acts by delivering copper to create functional hormone receptors.  (+info)

Oxidative stress markers in preovulatory follicular fluid in humans. (3/970)

Intensified peroxidation in the Graafian follicle may be a factor compromising the normal development of the oocyte. The aim of this study was to measure concentrations of three oxidative stress markers: conjugated dienes, lipid hydroperoxides and thiobarbituric acid-reactive substances, in preovulatory follicular fluids and sera of 145 women attending an in-vitro fertilization programme, and to correlate these concentrations with pregnancy outcome. Determinations were conducted either with or without an antioxidant (10 microM butylated hydroxytoluene) and an iron chelate (10 microM deferoxamine mesylate) to examine peroxidation associated with the methods used. Concentrations of conjugated dienes, lipid hydroperoxides and thiobarbituric acid-reactive substances in follicular fluid were all significantly lower than those in serum, both in the presence or absence of the antioxidant and iron chelate. These concentrations did not correlate with pregnancy outcome. In conclusion, the intensity of peroxidation in the Graafian follicle is much lower than that in serum. This gradient is the result of the lower rate of initiation of peroxidation in the follicular fluid, suggestive of the presence of efficient antioxidant defence systems in the direct milieu of the oocyte before ovulation. The concentrations of investigated oxidative stress markers in follicular fluid do not reflect the reproductive potential of oocytes.  (+info)

A role for coenzyme M (2-mercaptoethanesulfonic acid) in a bacterial pathway of aliphatic epoxide carboxylation. (4/970)

The bacterial metabolism of short-chain aliphatic alkenes occurs via oxidation to epoxyalkanes followed by carboxylation to beta-ketoacids. Epoxyalkane carboxylation requires four enzymes (components I-IV), NADPH, NAD(+), and a previously unidentified nucleophilic thiol. In the present work, coenzyme M (2-mercaptoethanesulfonic acid), a compound previously found only in the methanogenic Archaea where it serves as a methyl group carrier and activator, has been identified as the thiol and central cofactor of aliphatic epoxide carboxylation in the Gram-negative bacterium Xanthobacter strain Py2. Component I catalyzed the addition of coenzyme M to epoxypropane to form a beta-hydroxythioether, 2-(2-hydroxypropylthio)ethanesulfonate. Components III and IV catalyzed the NAD(+)-dependent stereoselective dehydrogenation of R- and S-enantiomers of 2-(2-hydroxypropylthio)ethanesulfonate to form 2-(2-ketopropylthio)ethanesulfonate. Component II catalyzed the NADPH-dependent cleavage and carboxylation of the beta-ketothioether to form acetoacetate and coenzyme M. These findings evince a newfound versatility for coenzyme M as a carrier and activator of alkyl groups longer in chain-length than methane, a function for coenzyme M in a catabolic pathway of hydrocarbon oxidation, and the presence of coenzyme M in the bacterial domain of the phylogenetic tree. These results serve to unify bacterial and Archaeal metabolism further and showcase diverse biological functions for an elegantly simple organic molecule.  (+info)

Importance of the beta12-beta13 loop in protein phosphatase-1 catalytic subunit for inhibition by toxins and mammalian protein inhibitors. (5/970)

Type-1 protein serine/threonine phosphatases (PP1) are uniquely inhibited by the mammalian proteins, inhibitor-1 (I-1), inhibitor-2 (I-2), and nuclear inhibitor of PP1 (NIPP-1). In addition, several natural compounds inhibit both PP1 and the type-2 phosphatase, PP2A. Deletion of C-terminal sequences that included the beta12-beta13 loop attenuated the inhibition of the resulting PP1alpha catalytic core by I-1, I-2, NIPP-1, and several toxins, including tautomycin, microcystin-LR, calyculin A, and okadaic acid. Substitution of C-terminal sequences from the PP2A catalytic subunit produced a chimeric enzyme, CRHM2, that was inhibited by toxins with dose-response characteristics of PP1 and not PP2A. However, CRHM2 was insensitive to the PP1-specific inhibitors, I-1, I-2, and NIPP-1. The anticancer compound, fostriecin, differed from other phosphatase inhibitors in that it inhibited wild-type PP1alpha, the PP1alpha catalytic core, and CRHM2 with identical IC(50). Binding of wild-type and mutant phosphatases to immobilized microcystin-LR, NIPP-1, and I-2 established that the beta12-beta13 loop was essential for the association of PP1 with toxins and the protein inhibitors. These studies point to the importance of the beta12-beta13 loop structure and conformation for the control of PP1 functions by toxins and endogenous proteins.  (+info)

Degradation of trichloroethene by a linear-plasmid-encoded alkene monooxygenase in Rhodococcus corallinus (Nocardia corallina) B-276. (6/970)

Rhodococcus corallinus (formerly Nocardia corallina) B-276, isolated with propene as sole carbon and energy source, is able to oxidize trichloroethene (TCE). Glucose- or propene-grown R. corallinus B-276 cells exhibited no difference in TCE degradation efficiency. TCE degradation was found to be growth-phase-dependent and maximum rates were monitored with stationary-phase cells. K(m) and Vmax values for TCE degradation of R. corallinus B-276 grown in nutrient broth medium in the presence of glucose were 187 microM and 2.4 nmol min-1 (mg protein)-1, respectively. Escherichia coli recombinants harbouring and expressing the alkene monooxygenase genes of R. corallinus B-276 exhibited the ability to degrade TCE. This result provides clear evidence that the alkene monooxygenase of R. corallinus B-276 catalyses TCE oxidation. R. corallinus B-276 was shown to contain four linear plasmids, pNC10 (70 kb), pNC20 (85 kb), pNC30 (185 kb) and pNC40 (235 kb). The observation that pNC30-deficient strains had lost the ability to grow on propene suggested that the genes of the propene degradation pathway are encoded by the linear plasmid pNC30. Southern blot analysis with cloned alkene monooxygenase genes from R. corallinus B-276 revealed a positive hybridization signal with the linear plasmid pNC30. This result clearly shows that the alkene monooxygenase is encoded by the linear plasmid pNC30. Eleven short-chain-alkene-oxidizing strains were screened for the presence of linear plasmids. Among these, four propene-oxidizing Rhodococcus strains and one ethene-oxidizing Mycobacterium strain were found to contain linear megaplasmids. Southern blot analysis with the alkene monooxygenase revealed positive signals with linear plasmids of two propene-oxidizing Rhodococcus ruber strains. These results indicate that homologous alkene monooxygenases are encoded by linear plasmids in R. ruber strains.  (+info)

Characterization of the gene cluster involved in isoprene metabolism in Rhodococcus sp. strain AD45. (7/970)

The genes involved in isoprene (2-methyl-1,3-butadiene) utilization in Rhodococcus sp. strain AD45 were cloned and characterized. Sequence analysis of an 8.5-kb DNA fragment showed the presence of 10 genes of which 2 encoded enzymes which were previously found to be involved in isoprene degradation: a glutathione S-transferase with activity towards 1,2-epoxy-2-methyl-3-butene (isoI) and a 1-hydroxy-2-glutathionyl-2-methyl-3-butene dehydrogenase (isoH). Furthermore, a gene encoding a second glutathione S-transferase was identified (isoJ). The isoJ gene was overexpressed in Escherichia coli and was found to have activity with 1-chloro-2,4-dinitrobenzene and 3,4-dichloro-1-nitrobenzene but not with 1, 2-epoxy-2-methyl-3-butene. Downstream of isoJ, six genes (isoABCDEF) were found; these genes encoded a putative alkene monooxygenase that showed high similarity to components of the alkene monooxygenase from Xanthobacter sp. strain Py2 and other multicomponent monooxygenases. The deduced amino acid sequence encoded by an additional gene (isoG) showed significant similarity with that of alpha-methylacyl-coenzyme A racemase. The results are in agreement with a catabolic route for isoprene involving epoxidation by a monooxygenase, conjugation to glutathione, and oxidation of the hydroxyl group to a carboxylate. Metabolism may proceed by fatty acid oxidation after removal of glutathione by a still-unknown mechanism.  (+info)

Porcine kidney microsomal cysteine S-conjugate N-acetyltransferase-catalyzed N-acetylation of haloalkene-derived cysteine S-conjugates. (8/970)

N-Acetylation of xenobiotic-derived cysteine S-conjugates is a key step in the mercapturic acid pathway. The aim of this study was to investigate the N-acetylation of haloalkene-derived S-haloalkyl and S-haloalkenyl cysteine S-conjugates by porcine kidney cysteine S-conjugate N-acetyltransferase (NAcT). A radioactive assay for the quantification of NAcT activity was developed as a new method for partial purification of the enzyme, which was necessitated by the substantial loss of activity during the immunoaffinity chromatography method. 3-[(3-Cholamidopropyl)dimethylammonio]-1-propane-sulfonate, rather than N,N-bis[3-gluconamidopropyl]deoxycholamide, was used to solubilize the NAcT from porcine kidney microsomes in the revised procedure. The partially purified NAcT was free of detectable aminoacylase activity. Although low acetyl-coenzyme A hydrolase activity was observed, its effect on the assay was minimized by addition of excess acetyl-coenzyme A in the NAcT assay mixture. Attempts to separate the residual hydrolase activity from NAcT by different chromatographic procedures were either unsuccessful or lead to inactivation of NAcT. Most of the cysteine S-conjugates studied were N-acetylated by NAcT. Although the apparent K(m) values for the cysteine S-conjugates studied differed by a factor of approximately 2.5 (124-302 microM), a greater than 15-fold difference in the apparent V(max) (0.75-15.6 nmol/h) and V(max)/K(m) (0.008-0.126 x 10(-3) l h(-1)) values was observed. These data show that a range of haloalkene-derived cysteine S-conjugates serve as substrates for pig kidney NAcT. The significant differences in cytotoxicity of these conjugates may be a result of more variable deacetylation rates of the corresponding mercapturates.  (+info)

The olefin metathesis reaction has become a widely used method for the construction of new carbon-carbon double bonds. The development of well-defined, ruthenium-based catalysts with high air- and moisture-stability and functional group tolerance has allowed synthetic chemists to exploit this reaction in many areas. The main goal of this thesis was to better understand the impact of changes in catalyst and monomer structure on the olefin metathesis reaction. The introduction of chelating alkylidene ligands to olefin metathesis catalysts has resulted in systems with high activity and stability that, for the most part, are active at or below room temperature. However, for some applications, catalysts that react only at higher temperatures are desirable. Chapter 2 describes the synthesis of latent olefin metathesis catalysts with chelating alkylidenes with a range of donor ligands: including phosphines, pyridines, imines, amines, and thioethers. The nature of the donor ligand was found to have a ...
2020 American Chemical Society. Reported herein is a modular, NiH-catalyzed system capable of proximal-selective hydroamination of unactivated alkenes with diverse amine sources. The key to the successful implementation of this approach is the promotion of NiH insertion into even highly substituted olefins via coordination of the bidentate directing group to the nickel complex. A wide range of primary and secondary amines can be installed in both internal and terminal unactivated alkenes with excellent regiocontrol under the optimized reaction conditions. This protocol is flexible and general for the preparation of a variety of valuable β- and γ-amino acid building blocks that would otherwise be difficult to synthesize. The utility of this transformation was further demonstrated by the site-selective late-stage modification of complex and medicinally relevant molecules. Combined experimental and computational studies illuminate the detailed reaction ...
TY - JOUR. T1 - Mechanistic Model for Enantioselective Intramolecular Alkene Cyanoamidation via Palladium-Catalyzed C-CN Bond Activation. AU - Frost, Grant B.. AU - Serratore, Nicholas A.. AU - Ogilvie, Jodi M.. AU - Douglas, Christopher J.. N1 - Funding Information: We thank National Institutes of Health for funding this work (R01 GM095559). We thank Prof. Steve Kass (UMN) for constructive feedback.. PY - 2017/4/7. Y1 - 2017/4/7. N2 - We studied key aspects of the mechanism of Pd-catalyzed C-CN bond activation and intramolecular enantioselective alkene cyanoamidation. An Abboud-Abraham-Kamlet-Taft (AAKT) linear solvation energy relationship (LSER) model for enantioselectivity was established. We investigated the impact of Lewis acid (BPh3), Lewis base (DMPU), and no additives. BPh3 additive led to diminished enantioselectivity and differing results in 13CN crossover experiments, initial rate kinetics, and natural abundance 12C/13C kinetic isotope effect measurements. We propose two catalytic ...
Qilei Zhu, David E. Graff, Robert R. Knowles:. https://pubs.acs.org/doi/10.1021/jacs.7b11144. ABSTRACT: Here we report a catalytic method for the intermolecular anti-Markovnikov hydroamination of unactivated alkenes using primary and secondary sulfonamides. These reactions occur at room temperature under visible light irradiation and are jointly catalyzed by an iridium(III) photocatalyst, a dialkyl phosphate base, and a thiol hydrogen atom donor. Reaction outcomes are consistent with the intermediacy of an N-centered sulfonamidyl radical generated via proton-coupled electron transfer activation of the sulfonamide N-H bond. Studies outlining the synthetic scope (,60 examples) and mechanistic features of the reaction are presented.. ...
Nickel-catalyzed 1,2-carboboration of alkenes is emerging as a useful method for chemical synthesis. Prior studies have been limited to only the incorporation of aryl groups. In this manuscript, a method for the 1,2-benzylboration of unactivated alkenes is presented. The reaction combines readily available alkenes,
see article for more reactions. Abstract. In the presence of ruthenium-based olefin metathesis catalysts and triphenylphosphine, α,β-unsaturated aldehydes can be olefinated with diazoacetates. A tandem transformation of terminal olefins to 1,3-dienoic olefins in a single operation based on olefin cross-metathesis and Wittig olefination has been developed.. ...
We can use the alkenes as fuel in aerospace, industry and so on, which not does only protect the natural environment, but it is also economic. In biological and curatorial fields, they can make much more contribution. Therefore people is trying to make alkenes in different ways, and trying their best to find the easiest and the most economic methods. 1 Making the alkene There are so many ways can make an alkene, usually we make the alkenes by elimination reactions. ,1,. i?? elimination reaction: Ethylene and propene are prepared on an industrial scale by the high temperature dehydrogenation of ethane and propane.. Both reactions involve i?? elimination of H2. Many reactions classified as dehydrogenations occur within the cells of living systems at 25 ?. (The enzyme indicated is a special kind, known as flavoprotein in reaction) Dehydrogenation of alkanes is not a practical laboratory synthesis for the vast majority of alkenes. The principal methods by which alkenes are prepared in the laboratory ...
see article for more reactions. Abstract. Cu-catalyzed formal hydroboration of terminal or 1,1-disubstituted alkenes with bis(pinacolato)diboron and methanol provides products with exceptional regiocontrol favoring the branched isomer. Subsequent photocatalytic cross-couplings using iridium and nickel cocatalysis enable a highly regioselective hydroarylation of terminal alkenes.. ...
The regioselective hydroboration of aliphatic internal alkenes remains a great challenge. Reported herein is an iridium-catalyzed hydroboration of aliphatic internal alkenes, providing distal-borylated products in good to excellent yields with high regioselectivity (up to 99:1). We also demonstrate that the C-B bond of the distal-borylated product can be readily converted into other functional groups. DFT calculations indicate that the reaction proceeds through an unexpected IrIII /IrV cycle. ...
This thesis describes the synthesis of supported Schrock-type initiators immobilised via polymer-bound alcohol and their activity in olefin metathesis, together with a parallel study of the synthesis and reactivity of their model homogeneous counterparts.;Chapter 1 presents an overview of the inorganic and organic supports used in order to achieve the heterogeneisation of a range of different homogenous catalysts. A review of the nature of various organic supports and examples of supported metalligand complexes are given. The terms olefin metathesis, and their corresponding metathesis reactions such as ROMP, RCM, ADMET, ROM, and cross metathesis are defined. A review of previously reported classical multi-component initiator systems, well-defined single component initiators, together with well-defined supported initiators for use in olefin metathesis reactions is given.;Chapter 2 describes the synthesis of diol ligands such as TADDOL and those based upon a pentanediol skeleton together with that ...
All alkenes undergo addition reactions with the hydrogen halides. For example, with ethene and hydrogen chloride, you get chloroethane: With but-2-ene you get 2-chlorobutane: Addition of HCl to Alkenes to Give Alkyl Chlorides by JAMES Description: Treatment of alkenes with hydrochloric acid (HCl) will result in the formation of alkyl chlorides. Addition to symmetrical alkenes. However, in … A hydrogen atom joins to one of the carbon atoms originally in the double bond, and a halogen atom to the other. Hydrogen halide addition to alkenes is a highly regioselective reactionbecause addition of the hydrogen halide across the double bond gives only one of the two possible con- stitutionally isomeric addition … For example, with ethene and hydrogen chloride, you get chloroethane: With but-2-ene you get 2-chlorobutane: Electrophilic addition of HCl to alkenes The carbenium ion, which is formed by protonation of an alkene by HCl, is subsequently attacked by the chloride anion resulting in a ...
Olefin cross-metathesis has been demonstrated to be a modular pathway for synthesis of a series of functionalized cellulose esters. As a proof of concept, cellulose acetate was acylated with two terminally olefinic acid chlorides, pent-4-enoyl chloride and undec-10-enoyl chloride, providing olefin-terminated cellulose esters with different side-chain lengths. These ω-unsaturated cellulose esters were then reacted with a variety of cross-metathesis partners, including acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, poly(ethylene glycol) methyl ether acrylate, and allyl alcohols, using Hoveyda-Grubbs 2nd generation catalyst. Complete conversion to cross-metathesis products was achieved in reactions with acrylic acid or acrylates using 3-5 mol% catalyst at 40 °C within 1 h. We further demonstrate successful hydrogenation of these α,β-unsaturated esters and acids, thereby eliminating the potential for radical-induced crosslinking during storage ...
In this study a number of cage alkenes were synthesised and tested for activity towards ringopening metathesis polymerisation (ROMP) with the commercially available catalysts 55 (Grubbs-I) and 56 (Grubbs-II). The first group of monomers are derivatives of tetracyclo[6.3.0.04,1105,9]undec-2-en-6-one (1). The synthesis of these cage alkenes are summarised in Scheme 7.1. The cage alkene 126b was synthesised by a Diels-Alder reaction between 1 and hexachlorocyclopentadiene (9, Scheme 7.2). The geometry of 126b was determined from XRD data. Knowledge of the geometry of 126b also established the geometry of 127 since conformational changes during the conversion from 126b to 127 are unlikely. Synthesis of the cage alkene 125 by the cycloaddition of 9 to 118 failed. The cage alkene exo-11-hydroxy-4,5,6,7,16,16-hexachlorohexacyclo[7.6.1.03,8.02,13.010,14]hexa-dec-5-ene (124, Scheme 7.3) could therefore not be prepared. Synthesis of 125 by reduction of 126b with various reduction systems was not ...
Stimulated by the strong interest in replacing fossil raw materials by renewable feedstocks in chemical industry, alkene metathesis of unsaturated bio-sourced olefins has been recently investigated with the objective of producing high-value molecules using green and atom economic strategies. It is due time to review what has been achieved in this field using terpenes and terpenoids as olefin metathesis partners. These substrates, derived from the isoprene structure, present different types of carbon-carbon double bonds that can be involved in self metathesis, ring closing metathesis, cross metathesis including ethenolysis, and ring opening metathesis. The successful achievements and remaining bottlenecks in this field will be discussed.
By postreducing the window size through silylation, 2nd generation Hoveyda-Grubbs catalyst was encapsulated in the nanocages of a mesoporous material SBA-1. The encapsulation efficiency of SBA-1 was up to 70 %, much higher than that of other mesoporous materials such as SBA-16, FDU-12, and MCM-41 (0-43 %). The successful encapsulation was confirmed by N2 sorption analysis and FTIR and diffusion reflectance UV/Vis spectroscopy. Such a SBA-1-encapsulated catalyst showed good activity in both olefin ring-closing metathesis and cross metathesis. A wide range of olefins could be transformed to the desired products with conversions of 27-100 %. The encapsulated catalyst showed more sensitive temperature effects than the homogeneous counterpart, reflecting the unique properties of the encapsulated catalyst. At reaction temperatures of 40-60 °C, the activity of the encapsulated catalyst was sufficiently comparable to that of the homogeneous catalyst for the cross metathesis of styrene-type substrates, ...
Li J,Liao SH,Xiong H,et al. Highly Diastereo- and Enantioselective Cyclopropanation of 1,2-Disubstituted Alkenes[J]. Angew. Chem.-Int. Edit.,2012,51(35):8838-8841 ...
Olefin metathesis is a powerful transformation based on catalytic reaction between alkenes. It allows a formation of a variety of structurally diverse molecules that cannot be easily prepared by alternative routes. Recently developed methods require relatively low catalyst loading and enable easy removal of residual ruthenium from the reaction product. These developments have attracted the attention of process chemists who add metathesis reaction to a toolbox of reliable methods for production of pharmaceuticals. This review presents selected examples of successful application of olefin metathesis in the synthesis of active pharmaceutical ingredients from laboratories within the pharmaceutical industry.. ...
A catalyst composition for polymerizing alpha-olefins is prepared by reacting a transition metal compound, e.g., titanium, with trimethylaluminum catalyst activator. In a preferred embodiment, the catalyst is supported on a porous refractory support and is prepared by additionally reacting a magnesium compound or an organomagnesium composition with the support.Also disclosed is a process for polymerizing alpha-olefins in the presence of the catalyst of the invention. The polymer products have higher bulk density and produce films of greater strength than polymers prepared with similar catalysts utilizing different alkyl-aluminum activators, e.g., triethylaluminum and tri-isobutylaluminum.
TY - JOUR. T1 - Ir(III)-catalyzed C7-position-selective oxidative C -H alkenylation of indolines with alkenes in air. AU - Pan, Shiguang. AU - Wakaki, Takayuki. AU - Ryu, Naoto. AU - Shibata, Takanori. PY - 2014. Y1 - 2014. N2 - An efficient method for C7-position-selective alkenylation of N-substituted indolines with alkenes is reported. Various 7-alkenylindolines were obtained in moderate to excellent yields in air in the presence of catalytic amounts of [CpIrCl2]2, AgOTf, and Cu(OAc)2. The protocol relies on the use of a carbonyl or carbamoyl group on the nitrogen atom of indoline as a directing group and is potentially applicable to the synthesis of 7-alkenylindoles and 7-alkylindoles. Lettin the cat outta the bag: An efficient IrIII-catalyzed oxidative coupling of N-substituted indolines with various alkenes at the C7-position in air assisted by a carbonyl or carbamoyl group as a directing group is reported. The catalyst was prepared from [CpIrCl2]2 and AgOTf. A variety of ...
Looking for monosubstituted alkene? Find out information about monosubstituted alkene. An alkene with the general formula RHC=CH2, where R is any organic group; only one carbon atom is bonded directly to one of the carbons of the... Explanation of monosubstituted alkene
What are the products of this alkene addition reaction? Solution 70P:Here, we are going to find out the products formed from the alkene addition reaction.Step 1: The molecules add across the double bond of alkene when addition reaction takes place. The addition of chlorine gas to the alkene molecule forms
|p| Direct and indirect roles of alkenes cannot be ignored, and this book will aim to include new findings in the alkenes (olefins) area, focusing on the industrial aspects of alkenes (olefins) production, separation, purification, kinetic, mechanism, wastewater treatment, etc. New simulation, modeling and mathematical (analytical, numerical and statistical) techniques are encouraged. Economical criteria in the production process, the downstream industries, and the industrial plans design for alkenes production/purification are also of interest. Therefore, all new research in this area (without any limitation) is welcome.|/p|
Today marks the Engle labs first foray into nickel catalysis. Congratulations to Joe, Van, and Mark for their paper in J. Am. Chem. Soc., which describes a new method to couple alkylzinc reagents, aryl iodides, and non-conjugated alkenes using a coordination control strategy. The work couldnt have happened with our collaborator Jason Chen, the Director…
I would not consider benzene to be an alkene because its chemical reactivity differs significantly from the reactivity of alkenes. For example, a classic chemical reaction involving alkenes is an addition reaction with elemental bromine. Benzene will not undergo this reaction and many other reactions characteristic of alkenes (e.g. catalytic hydrogenation, epoxidation, etc ...
This double bond is referred to, in the functional group terminology, as an alkene. You can locate carbonyl groups, alkenes, alkynes, and aromatics in the IR (infrared) spectrum, based on their shapes and relative locations. Hydrocarbons (compounds composed only of carbon and hydrogen) that contain only carbon-carbon single bonds are called alkanes. A C2H5 group is named as ethyl and a C3H7 group is called a propyl group. They are named using a prefix that designates the number of carbon atoms in the molecule and the suffix -ane (see below). You are doing the same thing when ypu have an alkyne. Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry You are numbering the C atoms starting with those that have priority functional groups as substituent. Ben Mills Science. In this case, the word methyl- would be put in front of the name of the parent alkene. The alcohol functional group takes precedence over the alkene ...
TY - JOUR. T1 - Adducts of Phenoxathiin and Thianthrene Cation Radicals with Alkenes and Cycloalkenes. AU - Shine, Henry J.. AU - Zhao, Bingjun. AU - Qian, Ding Quan. AU - Marx, John N.. AU - Guzman-Jimenez, Ilse Y.. AU - Thurston, John H.. AU - Ould-Ely, T.. AU - Whitmire, Kenton H.. PY - 2003/11/14. Y1 - 2003/11/14. N2 - Phenoxathiin cation radical perchlorate (PO.+ClO 4-) added stereospecifically to cyclopentene, cyclohexene, cycloheptene, and 1,5-cyclooctadiene to give 1,2-bis(5-phenoxathiiniumyl)cycloalkane diperchlorates (4-7) in good yield. The diaxial configuration of the PO+ groups was confirmed with X-ray crystallography. Unlike additions of thianthrene cation radical perchlorate (Th.+ClO4-) to these cycloalkenes, no evidence for formation of monoadducts was found in the reactions of PO .+ClO4-. This difference is discussed. Addition of Th.+ClO4- to five trans alkenes (2-butene, 2-pentene, 4-methyl-2-pentene, 3-octene, 5-decene) and four cis alkenes (2-pentene, 2-hexene, 2-heptene, ...
We describe herein a concise synthesis of (+)-neopeltolide, a marine macrolide natural product that elicits a highly potent antiproliferative activity against several human cancer cell lines. Our synthesis exploited the powerful bond-forming ability and high functional group compatibility of olefin metathesis and esterification reactions to minimize manipulations of oxygen functionalities and to maximize synthetic convergency. Our findings include a chemoselective olefin cross-metathesis reaction directed by H-bonding, and a ring-closing metathesis conducted under non-high dilution conditions. Moreover, we developed a 16-member stereoisomer library of 8,9-dehydroneopeltolide to systematically explore the stereostructure-activity relationships. Assessment of the antiproliferative activity of the stereoisomers against A549 human lung adenocarcinoma, MCF-7 human breast adenocarcinoma, HT-1080 human fibrosarcoma, and P388 murine leukemia cell lines has revealed marked differences in potency between ...
Catalytic cracking of alkenes takes place at elevated temperatures in the order of 773-833 K. In this work, the nature of the reactive intermediates at typical reaction conditions is studied in H-ZSM-5 using a complementary set of modeling tools. Ab initio static and molecular dynamics simulations are performed on different C4single bond C5 alkene cracking intermediates to identify the reactive species in terms of temperature. At 323 K, the prevalent intermediates are linear alkoxides, alkene π-complexes and tertiary carbenium ions. At a typical cracking temperature of 773 K, however, both secondary and tertiary alkoxides are unlikely to exist in the zeolite channels. Instead, more stable carbenium ion intermediates are found. Branched tertiary carbenium ions are very stable, while linear carbenium ions are predicted to be metastable at high temperature. Our findings confirm that carbenium ions, rather than alkoxides, are reactive intermediates in catalytic alkene cracking at 773 K. ...
[194 Pages Report] Check for Discount on Alpha Olefins Market by Type (1-Butene, 1-Hexene, 1-Octene, 1-Decene, 1-Dodecene), Application (Polyolefin Co-monomers, Surfactants and Intermediates, Lubricants, Fine Chemicals, Plasticizers, Oil Field Chemicals), and Region - Global Forecast to 2022 report by MarketsandMarkets. Alpha olefins market projected to reach USD 13.46billion by...
Title:Organocatalyzed Transient Dienamine-Mediated Diels-Alder Reactions between α,β-Unsaturated Ketones and Alkenes. VOLUME: 15 ISSUE: 5. Author(s):Iosune Arrastia, Ana Arrieta and Fernando P. Cossio*. Affiliation:Donostia International Physics Center, San Sebastian/Donostia, Donostia International Physics Center, San Sebastian/Donostia, Donostia International Physics Center, San Sebastian/Donostia. Keywords:Organocatalysis, diels-Alder reactions, cycloadditions, michael additions, pericyclic reactions, stepwise mechanisms.. Abstract:Organocatalyzed (4+2) cycloadditions (Diels-Alder reactions) are reviewed in this manuscript. Among the different catalytic alternatives, reactions involving α,β-unsaturated ketones and alkenes are considered. In these processes, substituted cyclohexanones are obtained via HOMO activation generated by amine organocatalysis that generate transient dienamine species. Both concerted and stepwise mechanisms are described. In most cases, excellent regio-, ...
Functionalized nitrogen and oxygen heterocycles are an abundant class of compounds found throughout nature and the chemical industry. Their frequent use in biologically active molecules and as ligands for the metals involved in asymmetric catalysis has made these compounds attractive synthetic targets. The research that follows describes my contributions to alkene and allene difunctionalization catalyzed by copper(II) in the preparation of functionalized pyrrolidines and tetrahydrofurans. In chapter 1 a brief review of the current carboaminaiton literature is given before a new copper(II)-catalyzed carboamination reaction that gives 6-Azabicyclo[3.2.1]octanes is discussed. These bridged bicyclic products are formed in a single step from N-sulfonyl-2-aryl-4-pentenamines. Over a range of sulfonyl protecting groups and aryl substituents, the resulting heterocycles were generally formed in good yields with good to excellent enantiomeric excess (ee). Both substrate desymmeterization and reaction ...
TY - GEN. T1 - Au-catalyzed epoxidation of linear alkene with molecular oxygen. AU - Jiang, Jian. AU - Oxford, Sean M.. AU - Fu, Baosong. AU - Kung, Mayfair C.. AU - Kung, Harold H. PY - 2010. Y1 - 2010. N2 - Selective oxidation of alkenes that possess allylic hydrogen typically requires the use of expensive and/or environmentally unfriendly oxidants such as peroxides, hydroperoxides, nitrous oxide, oxychlorides, and oxometal complexes. A much more desirable oxidant is molecular oxygen, which, however, only achieves good yield with alkenes without allylic hydrogen or by use with H2, which is potentially explosive. Highly selective epoxidation of propene and butene can be achieved using molecular oxygen in a dilute solution of water in methanol, catalyzed by a suspension of supported Au catalyst and titanium silicalite (TS-1), and using CO as the sacrificial reductant. Results of isotope labeling experiments further infer that the dominant reaction pathway proceeds via the formation of methyl ...
TY - JOUR. T1 - A comprehensive study of olefin metathesis catalyzed by Ru-based catalysts. AU - Poater, Albert. AU - Cavallo, Luigi. N1 - KAUST Repository Item: Exported on 2020-10-01. PY - 2015/9/29. Y1 - 2015/9/29. N2 - During a Ru-catalyzed reaction of an olefin with an alkylidene moiety that leads to a metallacycle intermediate, the cis insertion of the olefin can occur from two different directions, namely side and bottom with respect to the phosphine or N-heterocyclic ligand (NHC), depending on the first or second generation Grubbs catalyst. Here, DFT calculations unravel to which extent the bottom coordination of olefins with respect is favored over the side coordination through screening a wide range of catalysts, including first and second generation Grubbs catalysts as well as the subsequent Hoveyda derivatives. The equilibrium between bottom and side coordination is influenced by sterics, electronics, and polarity of the solvent. The side attack is favored for sterically less ...
Anderson, Donde R. and OLeary, Daniel J. and Grubbs, Robert H. (2008) Ruthenium-Olefin Complexes: Effect of Ligand Variation upon Geometry. Chemistry: a European Journal, 14 (25). pp. 7536-7544. ISSN 0947-6539. https://resolver.caltech.edu/CaltechAUTHORS:ANDcaej08 Anderson, D. R. and Kane, S. R. (2008) WASP-5b: a dense, very hot Jupiter transiting a 12th-mag Southern-hemisphere star. Monthly Notices of the Royal Astronomical Society, 387 (1). L4-L7. ISSN 0035-8711. https://resolver.caltech.edu/CaltechAUTHORS:20150304-112857372 Anderson, Donde R. and Ung, Thay and Mkrtumyan, Garik et al. (2008) Kinetic Selectivity of Olefin Metathesis Catalysts Bearing Cyclic (Alkyl)(Amino)Carbenes. Organometallics, 27 (4). pp. 563-566. ISSN 0276-7333. PMCID PMC2440574. https://resolver.caltech.edu/CaltechAUTHORS:20150311-104435790 Anderson, Donde R. and Lavallo, Vincent and OLeary, Daniel J. et al. (2007) Synthesis and reactivity of olefin metathesis catalysts bearing cyclic (alkyl) (amino) carbenes. ...
Although the [2 + 2] cycloaddition of alkenes and ketenes to form cyclobutanones is one of the few general methods for the construction of four-membered rings, the intramolecular version of this reaction had been little explored when we started work in this area in the early 1980s.109 These reactions differ from most other pericyclic reactions in that the ketene is a reactive intermediate, which will either rapidly form a cyclobutanone or decompose. The yield is determined by the relative rate of these two processes. Alkenyloxyketenes were chosen for the initial exploratory work because the alkenyloxy carboxylic acids were easily prepared by alkylation of unsaturated alcohols with α-bromo carboxylic acids. The electronic effects of the alkyl substituents on the alkene control the regiochemistry of the cycloaddition and the yield depends on the balance between the nucleophilicity of the alkene and steric hindrance.83,90,109 Leading bond formation occurs between the electrophilic carbonyl carbon ...
Tutorial covering the alkene hydroboration/oxidation reaction, which converts an alkene into an alcohol with anti-Markovnikov regioselectivity and syn stereoselectivity.
The development of intermolecular alkene aminopyridylation has great potential for quickly increasing molecular complexity with two valuable groups. Here we report a strategy for the photocatalytic aminopyridylation of alkenes using a variety of N-aminopyridinium salts as both aminating and pyridylating reagents. Using Eosin Y as a photocatalyst, amino and pyridyl groups are simultaneously incorporated into alkenes, affording synthetically useful aminoethyl pyridine derivatives under mild reaction conditions. Remarkably, the C4-regioselectivity in radical trapping with N-aminopyridinium salt can be controlled by electrostatic interaction between the pyridinium nitrogen and sulfonyl group of β-amino radical. This transformation is characterized by a broad substrate scope, good functional group compatibility, and the utility of this transformation was further demonstrated by late-stage functionalization of complex biorelevant molecules. Combining experiments and DFT calculations on the mechanism ...
TY - JOUR. T1 - Structure and biochemical properties of the alkene producing cytochrome p450 OleTJE (CYP152l1) from the jeotgalicoccus sp. 8456 bacterium. AU - Belcher, James. AU - McLean, Kirsty J.. AU - Matthews, Sarah. AU - Woodward, Laura S.. AU - Fisher, Karl. AU - Rigby, Stephen E.J.. AU - Nelson, David. AU - Potts, Donna. AU - Baynham, Michael T.. AU - Parker, David A.. AU - Leys, David. AU - Munro, Andrew W.. PY - 2014/3/7. Y1 - 2014/3/7. N2 - Background: OleTJE oxidatively decarboxylates fatty acids to produce terminal alkenes. Results: OleTJE is an efficient peroxide-dependent lipid decarboxylase, with high affinity substrate binding and the capacity to be resolubilized from precipitate in an active form. Conclusion: OleTJE has key differences in active site structure and substrate binding/mechanistic properties from related CYP152 hydroxylases. Significance: OleTJE is an efficient and robust biocatalyst with applications in biofuel production.. AB - Background: OleTJE oxidatively ...
Commonly, researchers must use rare, toxic metals and harsh reaction conditions to complete this transformation. Using a more sustainable catalyst for the reaction could solve such problems. Previous research has attempted to do so, yet with only limited success.. In a study recently published in the Journal of the American Chemical Society, researchers from Osaka University synthesized vicinal diamines from unactivated alkenes, using iodine as the catalyst. The synthetic protocol, appropriate for both anti- and syn-addition, is realistic, useful, and environmentally friendly.. We synthesized all diastereomers of vicinal diamines by anti-addition-adding two substituents to opposite sides of the double bond, says Satoshi Minakata, lead and senior author. In the presence of a molecular iodine catalyst, unactivated alkenes reacted with commercially available nosylamide and sodium hypochlorite, to yield the intended products in a stereospecific manner.. The reactions were complete within 12 ...
TY - JOUR. T1 - Efficient approach to medium-sized cyclic molecules containing (E)-Alkene via z to e photochemical isomerization in the presence of AgNO3-impregnated silica gel. AU - Machida, Kouhei. AU - Yoshida, Yuki. AU - Igawa, Kazunobu. AU - Tomooka, Katsuhiko. PY - 2018/1/1. Y1 - 2018/1/1. N2 - Efficient synthesis of medium-sized cyclic molecules containing an (E)-alkene was performed via the highly (E)selective photochemical isomerization of the (Z)-isomer, facilitated by AgNO3-impregnated silica gel.. AB - Efficient synthesis of medium-sized cyclic molecules containing an (E)-alkene was performed via the highly (E)selective photochemical isomerization of the (Z)-isomer, facilitated by AgNO3-impregnated silica gel.. UR - http://www.scopus.com/inward/record.url?scp=85040991533&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=85040991533&partnerID=8YFLogxK. U2 - 10.1246/cl.170937. DO - 10.1246/cl.170937. M3 - Article. VL - 47. SP - 186. EP - 188. JO - Chemistry ...
In alkenes we have a C=C bond and one bond is a sigma bond and the other one is pie bond. In ethene (simplest alkene) , Each of the carbon atoms is sp2-hybridized, and the double bond possesses a component and a component. The component results when an sp2 orbital of one carbon, oriented so that its axis lies along the inter-nuclear axis, overlaps with a similarly disposed sp2 orbital of the other carbon. Each sp2 orbital contains one electron, and the resulting bond contains two of the four electrons of the double bond. The bond contributes the other two electrons and is formed by a sideby-side overlap of singly occupied p orbitals of the two carbons. ...
Alkenes are from the family of hydrocarbons which also includes alkanes along with many other substances. Alkenes are very useful to us in our daily life, but do you know what they are?
Hindered phenol stabilized, stereoregular polymers of branched, higher alpha-olefins can be modified with unsaturated silanes, carboxylic acids, and/or carboxylic acid anhydrides in the presence of a free radical generator in the polymer melt. These polymers can also contain additional additives, such as glass fibers. An aliphatic thio compound is added after the grafting procedure for maximum beneficial effect.
Oxidation is an important route for the activation of chemical feedstocks for the synthesis of chemical intermediates. Alkene epoxidation by the electrophilic addition of oxygen to a carbon-carbon double bond is a major challenge in oxidation catalysis. In particular it is important to use molecular oxygen as the oxidant to avoid the formation of reagent by-products. We report the oxidation with air using graphite-supported gold-palladium catalysts of two alkenes, cis-cyclooctene, which gives mainly the epoxide, and crotyl alcohol (trans-but-2-en-1-ol). With cyclooctene, the reaction requires catalytic amounts of t-butyl hydroperoxide. The Au-Pd ratio has a major effect on the conversion with very low activities being associated with Au:Pd ratios of ca. 4:1 and 1:4 by weight. The selectivity to the epoxide is not affected by the Au:Pd ratio. With crotyl alcohol, t-butyl hydroperoxide was not required for activity. In the absence of Pd, crotonaldehyde was formed, but the introduction of Pd leads ...
A general strategy for visible-light-enabled site-selective trifluoromethylative pyridylation of unactivated alkenes has been developed using pyridines and triflic anhydride (Tf2O). Intriguingly, the N-triflylpyridinium salts, generated in situ from pyridines and Tf2O, serve as effective modular bifunctional reagents to install both CF3 and pyridyl groups to various olefins while controlling C4-selectivity in radical addition to the pyridine core. This synthetic route exhibited broad substrate scope under metal-free and mild photocatalytic conditions, granting efficient access to valuable C4-alkylated pyridines and quinolines without requiring prefunctionalization of the reaction site ...
Alkenes, like Alkanes, have carbon backbones but contain at least one carbon-carbon double bond. Double bonds are reactive and can be reduced to single bonds using hydrogen gas, pressure, and a catalyst, such as Pd or Pt. Alternatively, Alkenes can be reduced to Alkanes by reacting with Hydrogen gas over a Nickel catalyst. Nickel acts as a heterogeneous surface catalyst, weakening the H-H bonds in hydrogen, thus speeding up the reaction. This also leads to syn addition, where both of the hydrogens are added to the same side of the double bond. General Alkene Formula: CnH2n. Suffix: ene Example: CH2CH2 - Ethene See the alkane naming scheme for branched molecules, as the same principal applies to alkenes we simply retain the ene rather than the ane ending. However, the placement of the double bond matters when naming. Example: CH3(CH)2CH3 - 2-butene Example: CH2CHCH2CH3 - 1-butene IUPAC rules actually specify that alkenes should be named as but-1-ene, but-2-ene, and so on; but the practice ...
Alkyl bromides are key intermediates in many multi-step organic syntheses and are commonly synthesized from the hydrobromination of alkenes. While both the Markovnikov and anti-Markovnikov product can theoretically be produced from either the electrophilic addition mechanism or the radical mechanism, the electrophilic addition mechanism produces predominately the Markovnikov product while the radical mechanism mainly produces the anti-Markovnikov product. The regiochemistry of this reaction is controlled by the absence or presence of radicals. The addition of UV radiation or peroxide results in radical formation which yields predominately the anti-Markovnikov product. To improve the synthesis of the anti-Markovnikov product, conditions need to be modified to favor the production of radicals over carbocations. The objective of this research is to develop an efficient synthesis of the anti-Markovnikov alkyl bromides by generating hydrobromic acid from the in situ hydrolysis of phosphorous ...
A nitroalkene, or nitro olefin, is a functional group combining the functionality of its constituent parts, an alkene and nitro group, while displaying its own chemical properties through alkene activation, making the functional group useful in specialty reactions such as the Michael reaction or Diels-Alder additions. Nitroalkenes are synthesized by various means, notable examples include: Nitroaldol reactions such as the Henry reaction: Nitration of an alkene with nitryl iodide generated in-situ from silver nitrite and elemental iodine: Direct nitration of alkenes with nitric oxide and an aluminum oxide catalyst in acidic conditions: Direct nitration of alkenes with Clayfen (Iron(III) nitrate supported on Montmorillonite clay): Dehydration of nitro-alcohols: Nitroalkenes are useful intermediates for various chemical functionalities. A nitroalkene behaving as a Michael acceptor in the synthesis of Lycoricidine: Nitroalkene acting as an activated dienophile toward butadiene in an Diels-Alder ...
Bromine water test for alkenes. When an alkene is added to a solution of bromine water (left) the solution is de-colourised (right). Alkenes are hydrocarbons that contain a carbon-carbon double bond. The number of hydrogen atoms in an alkene is double the number of carbon atoms. Alkenes can de-colourise bromine water, while alkanes cannot. - Stock Image C029/0955
Olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds. Because of the relative simplicity of olefin metathesis, it often creates fewer undesired by-products and hazardous wastes than alternative organic reactions. For their elucidation of the reaction mechanism and their discovery of a variety of highly active catalysts, Yves Chauvin, Robert H. Grubbs, and Richard R. Schrock were collectively awarded the 2005 Nobel Prize in Chemistry. The reaction requires metal catalysts. Most commercially important processes employ heterogeneous catalysts, but well-defined homogeneous catalysts are also active. The heterogeneous catalysts are often prepared by in-situ activation of a metal halide using organoaluminium or organotin compounds, e.g. combining WCl6-EtOH-EtAlCl2. A typical catalyst support is alumina. Commercial catalysts are often based on molybdenum and ruthenium. Well-defined ...
Arnab Kumar Chatterjee was born in Calcutta, India in 1975. After completing a Bachelor of Arts in Chemistry and minor in Business from Northwestern University in 1997, he proceeded on to the California Institute of Technology in October 1998 to conduct his doctoral thesis research in the laboratory of Professor Robert H. Grubbs in the Division of Chemistry and Chemical Engineering. His doctoral research focused on understanding the reactivity and selectivity patterns of olefin cross-metathesis reactions using catalytic ruthenium alkylidenes. He also discovered previously unprecedented formation of trisubstituted olefins andunsaturated olefins by intermolecular olefin metathesis chemistry, greatly expanding the olefin cross-metathesis methodology. Subsequently, Professor Robert H. Grubbs was awarded the Nobel Prize in Chemistry in 2005 for his work in the area olefin metathesis. Upon completion of his doctoral research in September 2002, Arnab joined the Genomics Institute of the Novartis Research
In a previous post we went through the key reactions of the carbocation pathway. Its a family of reactions which proceed through 1) attack of an alkene upon an acid, forming a free carbocation, and 2) attack of a nucleophile upon the carbocation.. Although we saw that several key reactions of alkenes were consistent with this mechanism, it isnt the case for all. Take the bromination of alkenes, for instance.. Treatment of an alkene with bromine (Br2) in a chlorinated solvent (CHCl3, and CH2Cl2 are popular choices; CCl4 is often cited in textbooks*) leads to the formation of products containing two bromine atoms.. Observation #1: Bromination Proceeds with anti stereochemistry. Possibly the most interesting feature of this reaction is that the products follow a very predictable stereochemical pattern. For instance, in the reaction of cyclohexene with Br2, the two bromine atoms add to opposite faces of the alkene (anti stereochemistry). No syn products are observed.. ...
Advancement in metabolic engineering of microorganisms has enabled bio-based production of a range of chemicals, and such engineered microorganism can be used for sustainable production leading to reduced carbon dioxide emission there. One area that has attained much interest is microbial hydrocarbon biosynthesis, and in particular, alkanes and alkenes are important high-value chemicals as they can be utilized for a broad range of industrial purposes as well as drop-in biofuels. Some microorganisms have the ability to biosynthesize alkanes and alkenes naturally, but their production level is extremely low. Therefore, there have been various attempts to recruit other microbial cell factories for production of alkanes and alkenes by applying metabolic engineering strategies. Here we review different pathways and involved enzymes for alkane and alkene production and discuss bottlenecks and possible solutions to accomplish industrial level production of these chemicals by microbial fermentation ...
Advancement in metabolic engineering of microorganisms has enabled bio-based production of a range of chemicals, and such engineered microorganism can be used for sustainable production leading to reduced carbon dioxide emission there. One area that has attained much interest is microbial hydrocarbon biosynthesis, and in particular, alkanes and alkenes are important high-value chemicals as they can be utilized for a broad range of industrial purposes as well as drop-in biofuels. Some microorganisms have the ability to biosynthesize alkanes and alkenes naturally, but their production level is extremely low. Therefore, there have been various attempts to recruit other microbial cell factories for production of alkanes and alkenes by applying metabolic engineering strategies. Here we review different pathways and involved enzymes for alkane and alkene production and discuss bottlenecks and possible solutions to accomplish industrial level production of these chemicals by microbial fermentation.
Alkenes - Organic Chemistry 2 Chemistry Coach | The alkenes are studied in this chapter: the naming and properties of alkenes, the pi bond in chemistry, the preparation of alkenes with the Saytzev and the Hofmann rules, the degree of unsaturation of a chemical compound.
TY - JOUR. T1 - Rhodium-catalyzed anti-markovnikov addition of secondary amines to arylacetylenes at room temperature. AU - Sakai, Kazunori. AU - Kochi, Takuya. AU - Kakiuchi, Fumitoshi. PY - 2011/8/5. Y1 - 2011/8/5. N2 - An efficient method for synthesis of E-enamines by the anti-Markovnikov addition of secondary amines to terminal alkynes is described. The reaction of a variety of aryl- and heteroarylacetylenes proceeded at room temperature using a combination of a 8-quinolinolato rhodium complex and P(p-MeOC6H 4)3 as a catalyst. The products were obtained as enamines by simple bulb-to-bulb distillation.. AB - An efficient method for synthesis of E-enamines by the anti-Markovnikov addition of secondary amines to terminal alkynes is described. The reaction of a variety of aryl- and heteroarylacetylenes proceeded at room temperature using a combination of a 8-quinolinolato rhodium complex and P(p-MeOC6H 4)3 as a catalyst. The products were obtained as enamines by simple bulb-to-bulb ...
TY - CHAP. T1 - Hydroamination of alkenes. AU - Reznichenko, Alexander L.. AU - Hultzsch, Kai C.. N1 - Funding Information: Generous financial support by the National Science Foundation through a NSF CAREER Award (CHE 0956021) and the ACS Petroleum Research Fund (PRF #49109-ND1) is gratefully acknowledged. Publisher Copyright: © 2016 Organic Reactions, Inc. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.. PY - 2015. Y1 - 2015. N2 - The addition of an amine NH-functionality to alkenes (including vinyl arenes, conjugated dienes, allenes or ring-strained alkenes), the so-called hydroamination, represents a simple and highly atom-economical approach for the synthesis of nitrogen-containing products. A large variety of catalyst systems are available, ranging from alkali, alkaline earth, rare earth, Group 4 and Group 5 metals, to late transition metal catalysts, and, less prominent, Brønsted and Lewis acid-based catalyst systems. The mode of operation of these catalyst systems can vary ...
Peili Teo and Robert H. Grubbs of California Institute of Technology are reporting the preparation of ruthenium olefin cross-metathesis catalysts that improve selectivity for making Z (cis) alkenes, which are common in natural products and thus important to synthetic organic chemistry (Organometallics, DOI: 10.1021/om1007924). In the past, nearly all ring-opening and cross-metathesis reactions catalyzed by Grubbss ruthenium catalysts or by molybdenum catalysts such as those prepared by Massachusetts Institute of Technologys Richard R. Schrock predominantly yielded E (trans) alkenes. Schrock, Amir H. Hovedya of Boston College, and coworkers recently developed molybdenum monoalkoxide-pyrrolide catalysts that are successful in selectively making Z alkenes (C&EN, Sept. 13, page 33). Teo and Grubbs have followed suit with ruthenium N-heterocyclic carbene catalysts that contain bulky sulfonate and phosphate ligands. For example, the sulfonate catalyst shown is easy to prepare, air-stable, and has ...
TY - JOUR. T1 - New oxidative transformations of alkenes and alkynes under the action of diacetoxyiodobenzene. AU - Yusubov, M. S.. AU - Zholobova, G. A.. AU - Filimonova, I. L.. AU - Chi, Ki Whan. PY - 2004/8/1. Y1 - 2004/8/1. N2 - Treatment of alkenes and alkynes with diacetoxyiodobenzene activated by mineral and organic acids predominantly results in oxidative rearrangement. 1,4-Diphenylbutadiene in MeOH gives 3,4-dimethoxy-1,4-diphenylbut-1-ene.. AB - Treatment of alkenes and alkynes with diacetoxyiodobenzene activated by mineral and organic acids predominantly results in oxidative rearrangement. 1,4-Diphenylbutadiene in MeOH gives 3,4-dimethoxy-1,4-diphenylbut-1-ene.. KW - Alkenes. KW - Alkynes. KW - Diacetoxyiodobenzene. KW - Oxidative rearrangement. KW - Polyvalent iodine compounds. UR - http://www.scopus.com/inward/record.url?scp=14944340734&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=14944340734&partnerID=8YFLogxK. U2 - 10.1007/s11172-005-0027-8. DO - ...
TY - GEN. T1 - A new sinthetic application of (dichloroiodo)benzene in reactions with alkenes and alkynes. AU - Yusubova, R. J.. AU - Filimonov, V. D.. AU - Yusubov, M. S.. AU - Chi, Ki Whan. PY - 2004. Y1 - 2004. N2 - A convenient synthesis of vicinal methoxychlorides, methoxyiodides from alkenes and alkynes using PhICl2/CH3OH, I 2/PhICl2/CH3OH is described.. AB - A convenient synthesis of vicinal methoxychlorides, methoxyiodides from alkenes and alkynes using PhICl2/CH3OH, I 2/PhICl2/CH3OH is described.. KW - (dichloroiodo)Benzene. KW - Alkenes. KW - Alkynes. KW - Chloromethoxylation. KW - Iodomethoxylation. UR - http://www.scopus.com/inward/record.url?scp=29144459782&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=29144459782&partnerID=8YFLogxK. M3 - Conference contribution. AN - SCOPUS:29144459782. SN - 0780383834. SN - 9780780383838. VL - 2. SP - 97. EP - 98. BT - 8th Korea-Russia International Symposium on Science and Technology - Proceedings: KORUS 2004. ER - ...
Inhibitors of ruthenium olefin metathesis catalysts. Inhibitors of Ruthenium Olefin Metathesis Catalysts. Field of the Invention. The present invention relates to a catalytic system comprising a precatalyst, a precatalyst activator and the relationship between an inhibitor. Further, the invention relates to essay about education in south the use of the relationship and disposable income that this catalytic system in ring-opening metathesis polymerisation reactions. Background of the Invention. Polydicyclopentadiene (poly-DCPD) is obtained through Ring Opening Metathesis Polymerisation (ROMP) of essay be free in south dicyclopentadiene (DCPD). ROMP reaction is a metal carbene catalysed reaction using strained cyclic olefins to the relationship consumption and disposable income that produce a wide range of polymers. Poly-DCPD has excellent impact performance, superior chemical resistance, very low water absorption, very low dielectric constant and a high electrical strength. Todays commercial ...
A Modified System for the Synthesis of Enantioenriched N-Arylamines through Copper-Catalyzed Hydroamination Despite significant recent progress in copper-catalyzed enantioselective hydroamination chemistry, the synthesis of chiral N-arylamines, which are frequently found in natural products and pharmaceuticals, has not been realized. Initial experiments with N-arylhydroxylamine ester electrophiles were unsuccessful and instead, their reduction, in the presence of copper hydride (CuH) catalysts, was observed. We detail key modifications of our previously reported hydroamination protocols that led to broadly applicable conditions for the enantioselective net addition of secondary anilines across the double bond of styrenes, 1,1 -disubstituted alkenes, and terminal alkenes. NMR studies suggest that suppression of the undesired reduction pathway is the basis for the dramatic improvements in yield under this new protocol. Chapter 2 ...
Markovnikov vs Anti-Markovnikov in Alkene Addition Reactions Tutorial for Organic Chemistry Students -Step by step how to decide which products will form! Mark or AntiMark? Markovnikovs rule is less about memorizing what goes where and more about understanding that if theres a carbocation intermediate it will form on the most substituted carbon atom.
antibody-antibodies.com is the marketplace for research antibodies. Find the right antibody for your research needs. Oxidative Heck Reaction as a Tool for Para-selective Olefination of Aniline: A DFT Supported Mechanism.
Alkenes are known to react with hydrogen-terminated silicon surfaces to produce robust organic monolayers that are attached to the surface via covalent Si-C bonds. In this report we investigate the dependence of the rate of alkylation of porous silicon samples on the reaction time using photochemical initiation. The kinetics of the photochemical alkylation of hydrogen-terminated porous silicon by undec-1-ene in toluene were observed to be pseudo first order, however the apparent rate constant decreased as the concentration of undec-1-ene increased. This behaviour is opposite to what would be expected if the rate-limiting process was an elementary chemical reaction step involving the alkene. Instead, it suggests that transport of the alkene to reactive sites and in the correct orientation is the rate-limiting step. Comparison of the rates of alkylation of porous silicon by undec-1-ene and dimethoxytrityl (DMT)-undecenol is consistent with such an interpretation as the bulky DMT headgroup gives a ...
TY - JOUR. T1 - Methyltrioxorhenium supported on silica tethered with polyethers as catalyst for the epoxidation of alkenes with hydrogen peroxide. AU - Neumann, Ronny. AU - Wang, Tie Jun. N1 - Copyright: Copyright 2020 Elsevier B.V., All rights reserved.. PY - 1997. Y1 - 1997. N2 - Methyltrioxorhenium has been supported on silica functionalized with polyether tethers; in the absence of an organic solvent, this catalytic assembly catalysed the epoxidation of alkenes with 30% aqueous H2O2 in high selectivity compared to the ring opening products observed in homogeneous media.. AB - Methyltrioxorhenium has been supported on silica functionalized with polyether tethers; in the absence of an organic solvent, this catalytic assembly catalysed the epoxidation of alkenes with 30% aqueous H2O2 in high selectivity compared to the ring opening products observed in homogeneous media.. UR - http://www.scopus.com/inward/record.url?scp=0001882561&partnerID=8YFLogxK. UR - ...
A method is described for the gas chromatographic-electron-capture detection determination of alkenes via on-column bromination reactions. Pyridinium bromide perbromide (PBPB) was used as the Br2 source, and a cholesterol-glass beads mixture, treated with methanol, was used to remove excess Br2. The optimum ratio of cholesterol to glass beads was found to be 1:10, at which 93% of the bromine released from PBPB can be removed, without removal of the derivitized analytes. The conversion efficiency of alkene to the brominated derivative is extremely low (less than 2%) for ethene, whereas for propene and 1-butene it is 41 and 79%, respectively. For C3---C5 alkenes, this method is 200-300 times more sensitive than analysis of the underivitized analytes by using conventional flame ionization detection.. ...
This highlight discusses developments in transition metal-catalysed alkene and alkyne hydroacylation reactions over the past three years. The discussion summarizes the development of new catalyst systems for alkene and alkyne hydroacylation and applications to the synthesis of important ketone building blocks. The highlight captures transition metal-catalysed alkene and alkyne hydroacylation at a time of impressive growth when cobalt, nickel, ruthenium, and iridium catalysts are emerging as complements or replacements for traditional rhodium catalysts.
The domino three-component coupling reaction of arynes with DMF and active methylenes or methines was studied as a highly efficient method for preparing heterocycles. Coumarin derivative 5 was formed when diethyl malonate (2) or α-bromomalonate (3) were used as a C2-unit. In contrast, dihydrobenzofurans 7a and 7b were obtained by using α-chloroenolates generated from α-chloromalonates 4a and 4b and Et2Zn. The benzofuran 15a could be obtained by using ethyl iodoacetate (14) as a C1-unit. The one-pot conversion of dihydrobenzofurans 7a, 7b and 8a into benzofurans 15a and 15b was also studied. The direct synthesis of benzofuran 15b was achieved by using the active methine 18 having ketone and ester groups.
TY - JOUR. T1 - Enantioselective Hydroamination of Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer. AU - Roos, Casey B.. AU - Demaerel, Joachim. AU - Graff, David E.. AU - Knowles, Robert R.. PY - 2020/4/1. Y1 - 2020/4/1. N2 - An enantioselective, radical-based method for the intramolecular hydroamination of alkenes with sulfonamides is reported. These reactions are proposed to proceed via N-centered radicals formed by proton-coupled electron transfer (PCET) activation of sulfonamide N-H bonds. Noncovalent interactions between the neutral sulfonamidyl radical and a chiral phosphoric acid generated in the PCET event are hypothesized to serve as the basis for asymmetric induction in a subsequent C-N bond forming step, achieving selectivities of up to 98:2 er. These results offer further support for the ability of noncovalent interactions to enforce stereoselectivity in reactions of transient and highly reactive open-shell intermediates.. AB - An enantioselective, ...
The use of olefin cross metathesis in preparing functional polymers, through either pre-functionalisation of monomers or post-polymerisation functionalisation is growing in both scope and breadth. The broad functional group tolerance of olefin metathesis offers a wealth of opportunities for introducing a bro
TY - JOUR. T1 - Binding energy of d10 transition metals to alkenes by wave function theory and density functional theory. AU - Averkiev, Boris B.. AU - Zhao, Yan. AU - Truhlar, Donald G.. N1 - Copyright: Copyright 2010 Elsevier B.V., All rights reserved.. PY - 2010. Y1 - 2010. N2 - It is shown that new density functionals provide accurate binding energies for conjugated alkenes in Pd and Pt complexes.. AB - It is shown that new density functionals provide accurate binding energies for conjugated alkenes in Pd and Pt complexes.. KW - Binding energy. KW - Brueckner coupled cluster calculations. KW - Conjugated pi systems. KW - Density functionals. KW - Pd and Pt complexes. UR - http://www.scopus.com/inward/record.url?scp=77954175093&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=77954175093&partnerID=8YFLogxK. U2 - 10.1016/j.molcata.2010.03.016. DO - 10.1016/j.molcata.2010.03.016. M3 - Article. AN - SCOPUS:77954175093. VL - 324. SP - 80. EP - 88. JO - Journal of Molecular ...
Organometallic compound - Organometallic compound - Alkene and alkyne ligands: An alkene ligand contains a π bond between carbon atoms, C=C, which can serve as an electron pair donor in a metal complex, as in the case of Zeises salt (see above Historical developments). This complex may be prepared by bubbling ethylene, C2H4, through an aqueous solution of [PtCl4]2− in the presence of divalent tin, Sn(II), which aids in the removal of the chloride ion (Cl−) from the coordination sphere of the divalent platinum, Pt(II). The alkene ligand bonds to the metal centre by both electron donation and acceptance, similar to the situation with carbon monoxide. Electron donor-and-acceptor character between
cis-trans and E-Z naming scheme for alkenes | Alkenes and Alkynes | Organic chemistry | Khan Academy - lesson plan ideas from Spiral.
TY - JOUR. T1 - Sodium p-toluenesulfinate/copper(II) acetate in free radical reactions of 5-aryl substituted alkenes. AU - Wang, Sheow Fong. AU - Chuang, Che Ping. AU - Lee, Jia Han. AU - Liu, Shui Te. PY - 1999/2/19. Y1 - 1999/2/19. N2 - p-Toluenesulfonyl radical can be generated from sodium p- toluenesulfinate in aqueous acetic acid or formic acid. Sulfonyl radical mediating reaction of 5-aryl substituted alkenes with sodium p- toluenesulfinate/copper(II) acetate gave p-toluenesulfonylmethyl substituted naphthalene and isoquinoline derivatives. This reaction proceeded much faster in aqueous formic acid than in aqueous acetic acid. The cyclization mode (Ar2-6 vs Ar1-5) of the 5-phenyl-1-butyl radical is strongly dependent on the geometry of the tether of the radical intermediate.. AB - p-Toluenesulfonyl radical can be generated from sodium p- toluenesulfinate in aqueous acetic acid or formic acid. Sulfonyl radical mediating reaction of 5-aryl substituted alkenes with sodium p- ...
TY - JOUR. T1 - Anti-Markovnikov terminal and gem-olefin hydrosilylation using a κ 4 -diimine nickel catalyst. T2 - selectivity for alkene hydrosilylation over ether C-O bond cleavage. AU - Rock, Christopher L.. AU - Trovitch, Ryan. PY - 2019/1/1. Y1 - 2019/1/1. N2 - The phosphine-substituted α-diimine Ni precursor, ( Ph 2 PPr DI)Ni, has been found to catalyze alkene hydrosilylation in the presence of Ph 2 SiH 2 with turnover frequencies of up to 124 h −1 at 25 °C (990 h −1 at 60 °C). Moreover, the selective hydrosilylation of allylic and vinylic ethers has been demonstrated, even though ( Ph 2 PPr DI)Ni is known to catalyze allyl ester C-O bond hydrosilylation. At 70 °C, this catalyst has been found to mediate the hydrosilylation of ten different gem-olefins, with turnover numbers of up to 740 under neat conditions. Prior and current mechanistic observations suggest that alkene hydrosilylation takes place though a Chalk-Harrod mechanism following phosphine donor dissociation. AB - The ...
Preparation, properties and reactions of alkenes and alkynes: Physical properties of alkenes and alkynes (boiling points, density and dipole moments); Acidity of alkynes; Acid catalysed hydration of alkenes and alkynes (excluding the stereochemistry of addition and elimination); Reactions of alkenes with KMnO4 and ozone; Reduction of alkenes and alkynes; Preparation of alkenes and alkynes by elimination reactions; Electrophilic addition reactions of alkenes with X2, HX, HOX and H2O (X=halogen); Addition reactions of alkynes; Metal acetylides ...
Alkene Reactions Organic Chemistry Cheat Sheet Study Guide - See all the alkene reactions at a glance including reactants, reagents, products, regioselectivity and stereoselectivity showing Markovnikov and anti-Markovnikov, syn/anti additions and more
Author(s): Shen, Xiao; Nguyen, Thach T; Koh, Ming Joo; Xu, Dongmin; Speed, Alexander WH; Schrock, Richard R; Hoveyda, Amir H | Abstract: Macrocyclic compounds are central to the development of new drugs, but preparing them can be challenging because of the energy barrier that must be surmounted in order to bring together and fuse the two ends of an acyclic precursor such as an alkene (also known as an olefin). To this end, the catalytic process known as ring-closing metathesis (RCM) has allowed access to countless biologically active macrocyclic organic molecules, even for large-scale production. Stereoselectivity is often critical in such cases: the potency of a macrocyclic compound can depend on the stereochemistry of its alkene; alternatively, one isomer of the compound can be subjected to stereoselective modification (such as dihydroxylation). Kinetically controlled Z-selective RCM reactions have been reported, but the only available metathesis approach for accessing macrocyclic E-olefins entails
TY - JOUR. T1 - Transition-Metal-Free Catalysts for the Sustainable Epoxidation of Alkenes. T2 - From Discovery to Optimisation by Means of High Throughput Experimentation. AU - Lueangchaichaweng, Warunee. AU - Geukens, Inge. AU - Peeters, Annelies. AU - Jarry, Benjamin. AU - Launay, Franck. AU - Bonardet, Jean-Luc. AU - Jacobs, Pierre A.. AU - Pescarmona, Paolo P.. PY - 2012/2. Y1 - 2012/2. N2 - Transition-metal-free oxides were studied as heterogeneous catalysts for the sustainable epoxidation of alkenes with aqueous H2O2 by means of high throughput experimentation (HTE) techniques. A full-factorial HTE approach was applied in the various stages of the development of the catalysts: the synthesis of the materials, their screening as heterogeneous catalysts in liquid-phase epoxidation and the optimisation of the reaction conditions. Initially, the chemical composition of transition-metal-free oxides was screened, leading to the discovery of gallium oxide as a novel, active and selective ...
Alkenes are oxidized rapidly in the atmosphere by addition of OH and subsequently O2 leading to the formation of β-hydroxy peroxy radicals. These peroxy radicals react with NO to form β-hydroxy nitrates with a branching ratio α. We quantify α for C2 -C8 alkenes at 295 K ± 3 and 993 hPa. The branching ratio can be expressed as α = (0.045 ± 0.016) × N −(0.11 ± 0.05) where N is the number of heavy atoms (excluding the peroxy moiety), and listed errors are 2σ . These branching ratios are larger than previously reported and are similar to those for peroxy radicals formed from H abstraction from alkanes. We find the isomer distributions of β-hydroxy nitrates formed under NO-dominated peroxy radical chemistry to be different than the isomer distribution of hydroxy hydroperoxides produced under HO2 dominated peroxy radical chemistry. Assuming unity yield for the hydroperoxides implies that the branching ratio to form β-hydroxy nitrates increases with substitution of RO2 . Deuterium ...
Three stereoisomeric inhibitors of Pin1: (2R,5S)-, (2S,5R)- and (2S,5S)-Ac-pSer-Ψ[(Z)CH = C]-pipecolyl(Pip)-2-(2-naphthyl)ethylamine 1, that mimic L-pSer-D-Pro, D-pSer-L-Pro, and D-pSer-D-Pro amides respectively, were synthesized by a 13-step route. The newly formed stereogenic centers in the pipecolyl ring were introduced by Luche reduction, followed by stereospecific [2,3]-Still-Wittig rearrangement. The (Z)- to (E)-alkene ratio in the rearrangements were consistently 5.5 to 1. The stereochemistry at the original Ser α-carbon controlled the stereochemistry of the Luche reduction, but it did not affect the stereochemical outcome of the rearrangement, which consistently gave the (Z)-alkene. The epimerized by-product, (2S,5S)-10, resulting from the work-up after Na/NH3 debenzylation of (2S,5R)-9, was carried on to the (2S,5S)-1 isomer. Compound (2S,5S)-10 was resynthesized from the Luche reduction by-product, (2R,3R)-3, and the stereochemistry was confirmed by comparison of the optical ...
Advances in fossil fuel exploration have continued to drive availability of lower alkane feedstocks for the chemical industry. Lower alkanes are potential precursors to the plethora of basic organic chemicals. However, conversion of lower alkanes to valuable chemicals often involves indirect or multi-step reaction routes. Developing direct routes to obtain key organic chemicals from lower alkanes would benefit industry. Dehydrogenation of C2 and C3 alkanes are particularly of interest as alternatives to steam cracking and fluid catalytic cracking for obtaining C2 and C3 alkenes. This review highlights developments in non-oxidative, autothermal and oxidative dehydrogenation of C2 and C3 alkanes.We examine reaction routes to dehydrogenation of lower alkenes, and analyze the C-H activation mechanismof commercial catalysts in order to gain insight into rational design of improved catalysts for C2 and C3 alkane dehydrogenation at lower temperatures.. ...
Alkanes, Alkenes vs Alkynes Alkanes, alkenes and alkynes are all hydrocarbons with different structures and thus different physical and chemical properties.
Alkenes are ligands in transition metal alkene complexes. The two carbon centres bond to the metal using the C−C pi- and pi*- ... Most reactions of alkenes involve additions to this pi bond, forming new single bonds. Alkenes serve as a feedstock for the ... Linear alkenes of approximately five to sixteen carbon atoms are liquids, and higher alkenes are waxy solids. The melting point ... Most alkenes are also isomers of cycloalkanes. Acyclic alkene structural isomers with only one double bond follow: C2H4: ...
... is the simultaneous formation of C-N and C-C bonds across an alkene. This method represents a powerful ... Alkene substrates with a tethered nitrogen nucleophile have been used in these transformations to promote intramolecular ... Ney, J. E.; Wolfe, J. P. (2004). "Palladium-catalyzed synthesis of N-aryl pyrrolidines from γ-(N-arylamino) alkenes: evidence ... Generally, there are four categories of reaction modes for alkene carboamination. The first class is cyclization reactions, ...
Pyramidal alkenes are alkenes in which the two carbon atoms making up the double bond are not coplanar with their four ... these alkenes are very reactive compared to ordinary alkenes. They are liable to dimerization creating cyclobutane rings, or ... Pyramidal alkenes only are of interest because much can be learned from them about the nature of chemical bonding. Twisting to ... In alkenes 1.2 and 1.3 these angles are determined with X-ray crystallography as respectively 32.4°/22.7° and 27.3°/35.6°. ...
The systematic name of this enzyme class is alkene,NADH:oxygen oxidoreductase. This enzyme is also called alkene epoxygenase. ... In enzymology, an alkene monooxygenase (EC 1.14.13.69) is an enzyme that catalyzes the chemical reaction propene + NADH + H+ + ... Gallagher SC, Cammack R, Dalton H (1997). "Alkene monooxygenase from Nocardia corallina B-276 is a member of the class of ... Zhou NY, Jenkins A, Chan Kwo Chion CK, Leak DJ (1999). "The alkene monooxygenase from Xanthobacter strain Py2 is closely ...
... can produce two isomers, depending on the orientation of substituents on the alkene and the enone ... The less hindered faces of the enone and alkene react. Intramolecular enone-alkene cycloaddition may give either "bent" or " ... In the transition state for the first bond formation, the alkene tends to align itself so that the negative end of its dipole ... Enone-alkene cycloaddition has been applied to the synthesis of a cubane. The Favorskii rearrangement established the carbon ...
The barrier for the rotation of the alkene about the M-centroid vector is a measure of the strength of the M-alkene pi-bond. ... Since alkenes are mainly produced as mixtures with alkanes, the separation of alkanes and alkenes is of commercial interest. ... Cationic alkene complexes are susceptible to attack by nucleophiles. Metal alkene complexes are intermediates in many or most ... Alkene ligands lose much of their unsaturated character upon complexation. Most famously, the alkene ligand undergoes migratory ...
ISBN 978-0-470-74168-9. (Epoxides, Alkenes). ...
"Epoxyethane (Ethylene Oxide)". Alkenes menu. Chemguide. Retrieved 5 October 2009. van Os; N. M., eds. (1998). Nonionic ... Oxidation by peroxy acids is efficient for higher alkenes, but not for ethylene. The above reaction is slow and has low yield, ...
"Alkenes from Tosylhydrazones". Org. React. 23 (3): 405-507. doi:10.1002/0471264180.or023.03. ISBN 0471264180. Schreiber, J.; ...
... alkenes > alkynes Because the Diels-Alder reaction exchanges two π bonds for two σ bonds, it is intrinsically thermodynamically ...
... and Z-alkenes. As an alkene-generating transformation, the Bamford-Stevens reaction has broad utility in synthetic methodology ... The mechanism of this transformation is thought to proceed in a manner similar to the synthesis of alkenes through the Bamford- ... The Bamford-Stevens reaction is a chemical reaction whereby treatment of tosylhydrazones with strong base gives alkenes. It is ... Shapiro, R. H. (March 1976). "Alkenes from Tosylhydrazones". Organic Reactions. Vol. 23. New York: Wiley. pp. 405-507. ISBN 0- ...
This reaction is relevant to the catalytic production of butenes and related alkenes. Unsubstituted metallacyclopentanes adopt ... In the evolution of heterogeneous alkene metathesis catalysts, metallacyclopentanes are invoked as intermediates in the ... Thus, metallacyclopentane intermediates are proposed to isomerize to metallacyclobutanes, which can eliminate alkene giving the ... alkenes". Advances in Heterocyclic Chemistry. 39: 237-279. doi:10.1016/S0065-2725(17)30059-4. Grubbs, Robert H.; Miyashita, ...
The four main categories are (1) nucleophilic attack on an alkene alkyne, or allyl ligand and (2) insertion of the alkene into ... First, the catalyst is activated by amide exchange, generating the active catalyst (i). Next, the alkene inserts into the Ln-N ... Müller, T.E.; Hultzsch, K.C.; Yus, M.; Foubelo, F.; Tada, M. (2008). "Hydroamination: Direct Addition of Amines to Alkenes and ... Both systems produced the desired allyl amines in high yield, which contain an alkene that can be further functionalized ...
... trans alkenes tend to have higher melting points and lower solubility in inert solvents, as trans alkenes, in general, are more ... Thus, trans alkenes, which are less polar and more symmetrical, have lower boiling points and higher melting points, and cis ... These differences can be very small, as in the case of the boiling point of straight-chain alkenes, such as pent-2-ene, which ... Cis-trans notation cannot be used for alkenes with more than two different substituents. Instead the E-Z notation is used based ...
Treatment of the phenylaziridinylhydrazone with 0.3 equivalents of LDA in ether resulted in the alkene shown below with a cis: ... On the way to (-)-phytocassane D, a tricyclic ketone was subjected to Shapiro reaction conditions to yield the cyclic alkene ... To combat this problem, Yamamoto and coworkers developed an efficient stereoselective and regioselective route to alkenes using ... doi:10.1016/S0040-4039(00)75263-4. Shapiro, Robert H. (1976). "Alkenes from Tosylhydrazones". Organic Reactions. Org. React. ...
It can be purified by recrystallization from 90 to 95 °C water (10 g of NBS for 100 mL of water). NBS will react with alkenes 1 ... Haufe, G.; Alvernhe, G.; Laurent, A.; Ernet, T.; Goj, O.; Kröger, S.; Sattler, A. (2004). "Bromofluorination of alkenes". ... The preferred conditions are the portionwise addition of NBS to a solution of the alkene in 50% aqueous DMSO, DME, THF, or tert ... Preparative aspects of electrophilic three-component reactions with alkenes]. J. Prakt. Chem. 333 (5): 677-698. doi:10.1002/ ...
In oxymercuration, the alkene reacts with mercuric acetate (AcO-Hg-OAc) in aqueous solution to yield the addition of an ... For example, using an alkyne instead of an alkene yields an enol, which tautomerizes into a ketone. Using an alcohol instead of ... Oxymercuration is not limited to an alkene reacting with water to add hydroxyl and mercury groups. The carbon-mercury structure ... The oxymercuration reaction is an electrophilic addition organic reaction that transforms an alkene into a neutral alcohol. ...
"Cycloaddition reactions of alkenes". The Alkenes: Vol. 1 (1964). Chichester, UK: John Wiley & Sons, Ltd. pp. 739-953. doi: ...
... but give carboxylic acids instead of aldehydes for terminal alkenes. Marc G. Loudon (2002). "Addition Reactions of Alkenes". ... This means that one mole of hydroborane will undergo the reaction with three moles of alkene. Furthermore, it is not necessary ... This hydroboration is repeated two additional times, successively reacting each B-H bond so that three alkenes add to each BH3 ... The reaction sequence is also stereospecific, giving syn addition (on the same face of the alkene): the hydroboration is syn- ...
The cis alkenes, due to their U-bending shape, cannot arrange themselves as closely as the trans ones, so they will have lower ... In alkene ligand, the bonding structure can be described by Dewar-Chatt-Duncanson model. In this case, the π electron density ... An example of this is NBS bromination reaction with alkene. The N−Br bond in NBS is weak so that much Br free radical will form ... Alkenes are more affected by number of electrons and have lower boiling points than alkanes. The boiling and melting points ...
... s are usually prepared by treatment of an alkene with a halogen, in the presence of water. The reaction is a form of ... "Addition Reactions of Alkenes". Virtual Textbook of Organic Chemistry. Archived from the original on 2012-12-14. {{cite web}}: ...
Gilbert, John C.; Martin, Stephen F. (2010). "10.6 - Bromination of Alkenes". Experimental Organic Chemistry: A Miniscale and ... Stilbene undergoes reactions typical of alkenes. Trans-stilbene undergoes epoxidation with peroxymonophosphoric acid, H3PO5, ...
Semihydrogenation affords cis alkenes. Metal-alkyne complexes are also intermediates in the metal-catalyzed trimerization and ... Metal alkyne complexes are intermediates in the semihydrogenation of alkynes to alkenes: C2R2 + H2 → cis-C2R2H2 This ... MgCl2 The coordination of alkynes to transition metals is similar to that of alkenes. The bonding is described by the Dewar- ... "Catalytic Stereoselective Semihydrogenation of Alkynes to E-Alkenes". Angew. Chem. Int. Ed. 52 (3): 806-808. doi:10.1002/anie. ...
Alkene dihydroxylation by osmium tetroxide is an old and extremely useful method for the functionalization of olefins. However ... In his original report Sharpless suggested the reaction proceeded via a [2+2] cycloaddition of OsO4 onto the alkene to give an ... It is often difficult to obtain high diastereoselectivity on cis-disubstituted alkenes when both ends of the olefin have ... In general Sharpless asymmetric dihydroxylation favors oxidation of the more electron-rich alkene (scheme 1). In this example ...
Efficient generation of radicals capable of attacking the alkene double bond of vinyl monomers. Adequate solubility in the ... A variety of organic molecules including alkenes, alkynes, and alkanes undergo polymerization to high molecular weight products ... "The Polymerization of Alkenes". ChemGuide. Retrieved 1 April 2010. Alfrey, Turner; Price, Charles C. (1947). "Relative ... Chain Transfer Free Radical Vinyl Polymerization The Polymerization of Alkenes Polymer Synthesis Radical Reaction Chemistry ...
Skeletal formulas can depict cis and trans isomers of alkenes. Wavy single bonds are the standard way to represent unknown or ... Liu, Xin (2021-12-09). "2.1 Structures of Alkenes". {{cite journal}}: Cite journal requires ,journal= (help) "Friedrich August ...
It adds across alkenes. Illustrative is the synthesis of selenoureas from cyanamides: H2Se gas is used to dope semiconductors ...
Vinyl derivatives are alkenes. If activated by an adjacent group, the increased polarization of the bond gives rise to ...
"Alkenes from Dehydration of Alcohols". Chemistry LibreTexts. 2 October 2013. Retrieved 9 May 2022. Rossini FD (1937). "Heats of ... In the presence of acid catalysts, alcohols can be converted to alkenes such as ethanol to ethylene. Typically solid acids such ...
The corresponding alkyls polymerize alkenes. The synthesis of a tris(allyl)scandium complex is analogous to the above methods, ...
... the most stable alkene is the major product. That is to say, the most highly substituted alkene (the alkene with the most non- ... Naming Alkenes[edit , edit source]. Alkenes are named as if they were alkanes, but the "-ane" suffix is changed to "-ene". If ... An internal alkene (the double bond not on the terminal carbon) is more stable than a terminal alkene (the double bond is on a ... Haloalkanes ,Alkenes, Alkynes ,, Alkenes are aliphatic hydrocarbons containing carbon-carbon double bonds and general formula C ...
And then your alkene comes along. And your alkene is also flat, right? The portion of the molecule that contains the double ... So lets say your alkene-- lets do that ring again, it wasnt a very good one-- so lets say your alkene looked something like ... So the alkene is reduced by the addition of these two hydrogens. And youll see other definitions for oxidation states. Youll ... And you can see theres an alkene on this. So if I took this alpha-pinene molecule and I wanted to hydrogenate it, I could use ...
... alkene in English->English dictionary. Search over 14 million words and phrases in more than 510 language pairs. ... alkene aplauz kopile Plans unbuilt plot pavor spielen spółdzielczy swearword cara Facile à démonter rysownik zaduma the last ...
Efficient Trifluoromethylation of Alkenes. Author: ChemistryViews. Molecules bearing trifluoromethyl groups have been widely ... Simple alkenes can be used as substrates and the reaction tolerates a wide range of functional groups. ...
Free Radical Reactions of Alkenes. 1. Addition of Radicals to Alkenes. Protons and other electrophiles are not the only ... From this analysis and the examples given here, you should be able to deduce structural formulas for the alkenes that give the ... Alkene Isomer. (CH3)2CHCH=CH2. 3-methyl-1-butene. CH2=C(CH3)CH2CH3. 2-methyl-1-butene. (CH3)2C=CHCH3. 2-methyl-2-butene. ... First, the alkene must be adsorbed on the surface of the catalyst along with some of the hydrogen. Next, two hydrogens shift ...
Xu Cheng describes the synthesis of Aromatic N-Heterocycles from alkenes and ammonia. ... Insertion of Ammonia into Alkenes to Build Aromatic N-Heterocycles. Xu Cheng describes the synthesis of Aromatic N-Heterocycles ... Read the full article Insertion of Ammonia into Alkenes to Build Aromatic N-Heterocycles ... the authors studied the direct insertion of ammonia into alkenes to build aromatic N-heterocycles with electricity as the ...
2. ALKENES MARKET IN ITALY. 2.1. Overview of alkenes market. 2.2. Producers of alkenes, including contact details and product ... 5. ALKENES CONSUMERS IN ITALIAN MARKET. 5.1. Downstream markets of Alkenes (Ethylene, Propylene, Butylene, Butadiene) in Italy ... 3. ITALYS FOREIGH TRADE IN ALKENES. 3.1. Export and import of ethylene: volume, structure, dynamics. 3.2. Export and import of ... Alkenes (Ethylene, Propylene, Butylene, Butadiene) Market in Italy: Business Report 2022. * Report ...
Chaoyang Dai (1998). Homogeneous catalysis, synthesis of liquid crystals to diboration of alkenes. UWSpace. http://hdl.handle. ...
Alkenes are oxidized to diols and alkynes are oxidized to diones. The alkanes in this situation do not react with the potassium ... Reactivity of Alkanes and Alkenes is shared under a not declared license and was authored, remixed, and/or curated by ... It should be noted that alkenes and alkynes react with bromine to form dibromides. ... Alkenes : property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+,,c__DisplayClass226_0.,PageSubPageProperty,b ...
... addition of oxabicyclic alkenes catalyzed by a platinum(ii) catalyst was investigated by M06-2X/6-311G(d,p) using density ... center to one of the closer enantiotopic carbon atoms in an alkene of the oxabicyclic alkenes. The theoretically predicted ... The mechanism of an asymmetric ring-opening (ARO) addition of oxabicyclic alkenes catalyzed by a platinum(II) catalyst was ... Study on the mechanism of platinum(ii)-catalyzed asymmetric ring-opening addition of oxabicyclic alkenes with arylboronic acids ...
An ene reductase from Clavispora lusitaniae for asymmetric reduction of activated alkenes.. Ni Y, Yu HL, Lin GQ, Xu JH., Enzyme ... Asymmetric reduction of activated alkenes using an enoate reductase from Gluconobacter oxydans. Richter N, Gröger H, Hummel W ( ... Richter N, Gröger H, Hummel W. Asymmetric reduction of activated alkenes using an enoate reductase from Gluconobacter oxydans. ... N. Richter, H. Gröger, and W. Hummel, "Asymmetric reduction of activated alkenes using an enoate reductase from Gluconobacter ...
A noble-metal-free, photo-induced decarboxylative Heck-type coupling of terminal alkenes with alkyl carboxylic acids was ... Photo-induced Decarboxylative Heck-Type Coupling of Unactivated Aliphatic Acids and Terminal Alkenes in the Absence of ...
What are the conditions for the hydration of alkenes?. Hydration of Alkenes The net addition of water to alkenes is known as ... Can you go from an alcohol to an alkene?. Converting an alcohol to an alkene requires removal of the hydroxyl group and a ... The result involves breaking the pi bond in the alkene and an OH bond in water and the formation of a C-H bond and a C-OH bond ... Which of the following alcohols will be most easily dehydrated to give an alkene?. The alcohol that is dehydrated most easily ...
Specifically, this alkene-protection strategy was used to circumvent an undesired cyclisation reaction during a late-stage acid ... Studies towards squalene synthase inhibitors : total synthesis of 6,7-dideoxysqualestatin h5 via an alkene-protection strategy ... a concise route to synthesise α-diazo-ε-ketoesters was also developed that demonstrates the utility of chemoselective alkene ...
New Pathways to Advance Adsorbent Technologies for Alkene Purification: Research carried out in collaboration with beamline ... alkene analogues: [Cu-Br•(alkene)]2 and [Cu-H•(alkene)]2. The alkene is released from the complex upon removal of the alkene ... Specifically, [Cu-H]3 is an attractive target for alkene-alkane separation due to its ability to rapidly adsorb ethene at near ... New Pathways to Advance Adsorbent Technologies for Alkene Purification The separation and purification of chemicals remains a ...
Find Free Online Alkenes Courses and MOOC Courses that are related to Alkenes ...
2.7 The reaction of alkenes with aqueous potassium manganate(VII). If alkenes are bubbled into, or the liquid shaken with, a ... Part 2. The chemistry of ALKENES - unsaturated hydrocarbons. Doc Browns Chemistry Advanced Level Pre-University Chemistry ... My advanced A level organic chemistry index of notes on alkenes. Index of GCSE level Oil - Useful Products Chemistry Revision ... Part 2.7 The reaction of alkenes with aqueous potassium manganate(VII) - oxidation to form diol alcohols. A redox reaction ...
Isomerism in Alkanes and Alkenes - Description of Isomers ...
... DSpace Repository. Valencià Castellano ... Iron(iii) oxamato-catalyzed epoxidation of alkenes by dioxygen and pivalaldehyde. Show full item record ... it is a moderately efficient non-heme catalyst for the aerobic epoxidation of alkenes with co-oxidation of pivalaldehyde.. ... oxamato-catalyzed epoxidation of alkenes by dioxygen and pivalaldehyde, Chemical communications, vol. 1997, p. 2283-2284. ...
... characterisation and selective partial hydrogenation of alkynes to Z-alkenes. Journal of Materials Chemistry, 21 (9). pp. 3030- ... characterisation and selective partial hydrogenation of alkynes to Z-alkenes ...
Studies Directed at the Synthesis of Optically Active Pretazettine via Intramolecular Nitrone/Alkene Cycloaddition Reactions ... Treatment of this alkene aldehyde with N-(α-methylbenzyl)hydroxylamine afforded a nitrone, which underwent intramolecular 1,3- ... Studies Directed at the Synthesis of Optically Active Pretazettine via Intramolecular Nitrone/Alkene Cycloaddition Reactions ...
To do so, the best-known methods are hydrogenation of alkenes. ... Home biology homework help Alkanes and alkenes Alkanes and ... What is the reaction mechanism for the addition of bromine to an alkene? Does the mechanism change if the solvent is changed? ... It would be formed from combining two methyl radicals:The electrophilic addition of bromine to alkene (non-aqueous media) ... The physical properties of alkenes and alkanes are similar.. They are colourless, nonpolar, combustable, and almost odorless. ...
9: Alkenes is shared under a CC BY-NC-ND 4.0 license and was authored, remixed, and/or curated by LibreTexts. ... Alkenes : property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+,,c__DisplayClass228_0.,PageSubPageProperty, ...
One-Pot Synthesis of CF3-Substituted Pyrazolines/Pyrazoles from Electron-Deficient Alkenes/Alkynes and CF3CHN2 Generated in ... One-Pot Synthesis of CF3-Substituted Pyrazolines/Pyrazoles from Electron-Deficient Alkenes/Alkynes and CF3CHN2 Generated in ... The [3+2] cycloaddition of CF3CHN2, generated in situ, with electron-deficient alkenes/alkynes affords CF3-substituted ...
Hydroamination of Alkenes and Alkynes with Group 2 Centred Catalysts. *Hill, Michael (PI) ...
Dive into the research topics of Direct catalytic anti-Markovnikov addition reactions of oxygen nucleophiles to simple Alkenes ... Direct catalytic anti-Markovnikov addition reactions of oxygen nucleophiles to simple Alkenes. ...
... dc.contributor.advisor. ... Rutheniumkatalysierte Addition von nicht aktivierten C(sp²)-H- und C(sp³)-H-Bindungen an Alkene. de. ... Ruthenium-catalyzed addition of unactivated C(sp²)-H and C(sp³)-H bonds to alkenes. de. ... Novel site-selective carboxylate assisted ruthenium-catalyzed hydroarylations of unactivated alkenes, bearing valuable ...
other: This is a GLP guideline study and is used in read-across from Alchisor CAL 123 (see Read Across Justification Document). The study merits a Klimisch 1 rating; Klimisch 2 when used for read-across. ...
our alkenes alkynes are those which have at least one double bond at least one double bond have like it was a single point ... hydrocarbon and saturated a dose of the double bond and triple let us discuss alkine sunao water alkenes alkynes are those ... hi everyone lets take a questionnaire the question is how will you distinguish between alkanes alkenes and alkynes have to ... will be cnh2n for the alkene ok can be verified here we have to carbon atoms c2h 2 into 2 is equal to c2h this is our alkene ...
... are alkenes found in bayberry and lime oil, respectively. Oil of turpentine, obtained by distilling the exudate from pine trees ... alkenes. *. In hydrocarbon: Natural occurrence. ) Myrcene and limonene, for example, are alkenes found in bayberry and lime oil ...
  • Alkenes and alkynes can be transformed into almost any other functional group you can name! (leslutinsduphoenix.com)
  • We will review their nomenclature, and also learn about the vast possibility of reactions using alkenes and alkynes as starting materials. (leslutinsduphoenix.com)
  • Reduction of alkynes is a useful method for the stereoselective synthesis of disubstituted alkenes. (leslutinsduphoenix.com)
  • The [3+2] cycloaddition of CF 3 CHN 2 , generated in situ, with electron-deficient alkenes/alkynes affords CF 3 -substituted pyrazolines/pyrazoles in quantitative yields. (enamine.net)
  • How will you distinguish between alkanes, alkenes and alkynes? (doubtnut.com)
  • Alkynes on partial reduction with H 2 in the presence of suitable catalysts yield alkenes. (organicmystery.com)
  • The presence of pi bonds in both alkenes and alkynes allows them to undergo Addition Reactions . (clutchprep.com)
  • Here we're going to say that alkenes and alkynes undergo addition reactions, so we're adding to them, in which elements add across their pi bonds to create new sigma bonds. (clutchprep.com)
  • You can treat alkenes and alkynes as functional groups. (rsc.org)
  • Free radical thermal cracking to give shorter alkanes and ionic catalytic cracking to give shorter alkanes and alkenes. (leslutinsduphoenix.com)
  • Here, we will discuss the addition reactions of alkenes. (plusinto.com)
  • Alkenes are aliphatic hydrocarbons containing carbon-carbon double bonds and general formula C n H 2n . (wikibooks.org)
  • Which of the following alcohols will be most easily dehydrated to give an alkene? (kembrel.com)
  • Alcohols containing a β-hydrogen on heating with concentrated sulphuric acid (H 2 SO 4 ) lose a molecule of water to form alkenes. (organicmystery.com)
  • Alternatively, the vapours of alcohols are passed over heated alumina at 623K-633K to form alkenes with the elimination of one molecule of water. (organicmystery.com)
  • Dimethyl maleate as substrate undergoes free radical cleavage under visible light irradiation, and the catalytic system composed of Ru(bpy) 3 2+ catalyzed the reduction of electron-deficient alkenes to get the saturated product dimethyl succinate [2] . (alfa-chemistry.com)
  • What is the decreasing reactivity order of halogen hydracids (HCl, HI, HBr) for addition reaction of alkenes? (theunconditionalguru.in)
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  • Hydrogenation of an alkene using hydrogen gas and a platinum (or palladium or nickel) catalyst. (khanacademy.org)
  • As shown in the energy diagram, the hydrogenation of alkenes is exothermic, and heat is released corresponding to the ΔE (colored green) in the diagram. (msu.edu)
  • For example, the following table lists the heats of hydrogenation for three C 5 H 10 alkenes which give the same alkane product (2-methylbutane). (msu.edu)
  • The relationship between reactants and products in addition reactions can be illustrated by the hydrogenation of alkenes to yield alkanes. (plusinto.com)
  • Furthermore, to address a key synthetic challenge in a previous synthesis of DDSQ, a concise route to synthesise α-diazo-ε-ketoesters was also developed that demonstrates the utility of chemoselective alkene ozonolysis in the presence of a diazo functionality. (bl.uk)
  • Based on reductive ozonolysis reaction, how do you distinguish between an alkene and alkyne? (doubtnut.com)
  • Compound A is an alkene, so, on ozonolysis it will give carbonyl compounds B and C. (teachoo.com)
  • Alpha-olefins (or α-olefins ) are a family of organic compounds which are alkenes (also known as olefins) with a chemical formula C x H 2x , distinguished by having a double bond at the primary or alpha (α) position. (gayatriindustries.net)
  • The study, completed in collaboration with beamline scientists at the U.S. Department of Energy's Advanced Photon Source (APS) at Argonne National Laboratory, describes the structure and reactivity of two new copper(I) complexes that exhibit a unique combination of low heat adsorption, high selectivity, good uptake capacity, and rapid kinetics for the separation of gaseous alkenes (i.e. , ethene and propene) from alkanes. (anl.gov)
  • Haloalkanes, also known as alkyl halides, on heating with a strong base such as alcoholic solution of potassium hydroxide eliminate one molecule of halogen acid (HCl, HBr or HI) to form alkenes. (organicmystery.com)
  • Since a large heat of reaction indicates a high energy reactant, these heats are inversely proportional to the stabilities of the alkene isomers. (msu.edu)
  • Novel site-selective carboxylate assisted ruthenium-catalyzed hydroarylations of unactivated alkenes, bearing valuable functional groups, with various (hetero)arenes has been accomplished. (uni-goettingen.de)
  • Whenever an alkene has 3 or 4 differing substituents, one must use the what's called the EZ nomenclature, coming from the German words, Entgegen (opposite) and Zusammen (same). (wikibooks.org)
  • Ruthenium catalysts are widely used in organic reactions such as reduction of electron-deficient alkenes, reduction of nitrogen functional groups and oxidation of benzyl halides. (alfa-chemistry.com)
  • The simplest source of two hydrogen atoms is molecular hydrogen (H 2 ), but mixing alkenes with hydrogen does not result in any discernible reaction. (msu.edu)
  • The Gibbs free energy profiles show that the rate-determining step involves the migration of an aryl group from the platinum( II ) center to one of the closer enantiotopic carbon atoms in an alkene of the oxabicyclic alkenes. (rsc.org)
  • Or, looking from the perspective of the X group, we can say that the X atom (or group) adds to the carbon that already has the greater number of carbon atoms: This is the regiochemistry of the reaction as it shows why one regioisomer (constitutional isomer) is formed preferentially over the other … Alkenes are reactive because they have a high-lying pair of π-bonding electrons. (plusinto.com)
  • In the previous post, we talked about the Markovnikov's rule and learned that in the addition reaction of HX to an unsymmetrical alkene, the H adds to the carbon that already has the greater number of hydrogen atoms. (plusinto.com)
  • It would be formed from combining two methyl radicals:The electrophilic addition of bromine to alkene (non-aqueous media) Alkenes are reactive molecules, particularly when compared to alkanes. (leslutinsduphoenix.com)
  • See image A. . Electrophilic addition reactions can occur in compounds containing pi bonds like the alkenes. (plusinto.com)
  • It was found that the hydrogen bonds between the oxabicyclic alkenes and water molecules promotes the platinum( II ) catalyst leaving the reaction system effortlessly and entering the next catalysis recycle. (rsc.org)
  • Xu Cheng describes the synthesis of Aromatic N-Heterocycles from alkenes and ammonia. (thieme.de)
  • Despite several challenges in pursuing applications of ammonia in organic synthesis (e.g., high bond dissociation energy or being a strong ligand for diverse metal species), the authors studied the direct insertion of ammonia into alkenes to build aromatic N-heterocycles with electricity as the driving force. (thieme.de)
  • All alkenes undergo addition reactions with the hydrogen halides. (plusinto.com)
  • Alkenes undergo addition reactions. (plusinto.com)
  • For example, with ethene and hydrogen chloride, you get chloroethane: Addition of Hydrogen Halides to Alkenes All alkenes undergo addition reactions with the hydrogen halides. (plusinto.com)
  • What type of reaction can alkenes undergo? (primrosekitten.org)
  • To hydrogenate an alkene, you need hydrogen gas and a metal catalyst, something like platinum or palladium or nickel. (khanacademy.org)
  • First, the alkene must be adsorbed on the surface of the catalyst along with some of the hydrogen. (msu.edu)
  • The mechanism of an asymmetric ring-opening (ARO) addition of oxabicyclic alkenes catalyzed by a platinum( II ) catalyst was investigated by M06-2X/6-311G(d,p) using density functional theory (DFT). (rsc.org)
  • A noble-metal-free, photo-induced decarboxylative Heck-type coupling of terminal alkenes with alkyl carboxylic acids was achieved in the absence of external oxidants through the synergistic combination of an organo photo-redox catalyst and a cobaloxime catalyst, with H 2 and CO 2 as the only byproducts. (organic-chemistry.org)
  • it is a moderately efficient non-heme catalyst for the aerobic epoxidation of alkenes with co-oxidation of pivalaldehyde. (uv.es)
  • Since the hydroboration procedure is most commonly used to hydrate alkenes in an anti-Markovnikov fashion, we also need to know the stereoselectivity of the second oxidation reaction, which substitutes a hydroxyl group for the boron atom. (msu.edu)
  • If alkenes are bubbled into, or the liquid shaken with, a neutral aqueous potassium manganate(VII), KMnO 4 (aq), an oxidation reaction occurs and a diol alcohol is formed at room temperature. (docbrown.info)
  • Action of Haloacids on Symmetric Alkenes: The addition of halogen acids like HCl, HBr or HI to a compound containing multiple bond is known as hydrohalogenation. (plusinto.com)
  • Simple alkenes can be used as substrates and the reaction tolerates a wide range of functional groups. (chemistryviews.org)
  • Since the hydrogen in HBr is s… The carbocations involved in hydrogen halide addition to alkenes are examples of reactive intermediates or unstable intermediates: species that react so rapidly that they never accu-mulate in more than very low concentration. (plusinto.com)
  • If there is more than one double bond in an alkene, all of the bonds should be numbered in the name of the molecule - even terminal double bonds. (wikibooks.org)
  • The first thing to keep in mind is that alkenes are planar and there's no rotation of the bonds, as we'll discuss later. (wikibooks.org)
  • Photosynthetic Fixation of CO2 in Alkenes by Heterogeneous Photoredox Catalysis with Visible Light. (bvsalud.org)
  • Alkenes react with halogen acid to form corresponding alkyl halide. (plusinto.com)
  • A recombinant enoate reductase from Gluconobacter oxydans was heterologously expressed, purified, characterised and applied in the asymmetric reduction of activated alkenes. (uni-bielefeld.de)
  • Ru(bpy) 3 2+ -mediated reduction of electron-deficient alkenes was described in 1981. (alfa-chemistry.com)
  • If the alkene contains only one double bond and that double bond is terminal (the double bond is at one end of the molecule or another) then it is not necessary to place any number in front of the name. (wikibooks.org)
  • Just take away the double bond and you'll end up with your alkene-like product. (khanacademy.org)
  • In the less complex alkenes used in earlier examples the plane of the double bond was often a plane of symmetry, and addition reagents could approach with equal ease from either side. (msu.edu)
  • This heat of reaction can be used to evaluate the thermodynamic stability of alkenes having different numbers of alkyl substituents on the double bond. (msu.edu)
  • Alkenes can present a unique problem, however in that the cis/trans notation sometimes breaks down. (wikibooks.org)
  • These findings have exciting implications for the development of new adsorbent materials that can significantly improve the energy efficiency and carbon footprint of industrial-scale alkene purification processes. (anl.gov)
  • Specifically, traditional approaches to improve adsorbing materials (e.g., increased capacity, increased selectivity) for alkene purification require the tradeoff of desirable properties. (anl.gov)
  • Hydration of Alkenes The net addition of water to alkenes is known as hydration. (kembrel.com)
  • What is the reaction mechanism for the addition of bromine to an alkene? (leslutinsduphoenix.com)
  • Can isomeric products be formed in the addition of bromine to an alkene? (leslutinsduphoenix.com)
  • 9.2: Addition of Hydrogen Halides to Symmetrical Alkenes Here, HBr will become the electrophile. (plusinto.com)
  • Addition of H B r to alkenes The simplest type of electrophilic reaction to visualize is the addition of a haloacid such as H B r to an isolated alkene. (plusinto.com)
  • Depending on the structure of the alkene and the specific reagents, the reactions can be regioselective and/or stereoselective. (plusinto.com)
  • The final section describes a preliminary study of a novel carbometallation reaction of allenic substrates for stereocontrolled preparation of fiinctionalised alkenes. (ucl.ac.uk)
  • 2009. Pressure and Temperature Dependence of the Reaction of Vinyl Radical with Alkenes II: Measured Rates and Predicted Product Distributions for Vinyl + Propene . (mit.edu)
  • Just enter your email address below and get the PDF as well as a classic exam preparation set for alkenes. (masterorganicchemistry.com)
  • Can you go from an alcohol to an alkene? (kembrel.com)
  • Converting an alcohol to an alkene requires removal of the hydroxyl group and a hydrogen atom on the neighbouring carbon atom. (kembrel.com)
  • The second one is incorrect because flipping the formula horizontally results in a lower number for the alkene. (wikibooks.org)
  • In this protocol, anti-Markovnikov hydrocarboxylation of alkenes with CO2 to an extended carbon chain is achieved with good functional group tolerance and specific regioselectivity under visible light irradiation. (bvsalud.org)
  • Vicinal dihalides on reaction with Zn lose a molecule of ZnX 2 to form alkenes. (organicmystery.com)
  • Based on crystal structures of the final product, the team were able to confirm that greater than 95% of the starting material [Cu-H] 3 converted into the dimeric-alkene derivative within 2 minutes at 10 bar. (anl.gov)
  • Specifically, this alkene-protection strategy was used to circumvent an undesired cyclisation reaction during a late-stage acid-catalysed 6,8- to 2,8- dioxabicyclo[3.2.1]octane rearrangement en route to DDSQ. (bl.uk)
  • Specifically we describe a method for Pd(0)-catalyzed alkene syn -1,2-carboboration and -silylation, allowing streightforward access to structural complex alkylboronates and -silanes. (englelab.com)
  • The alkene is released from the complex upon removal of the alkene source, and the complexes convert back to their original trimeric structure. (anl.gov)
  • What other product is produced during the incomplete combustion of an alkene? (primrosekitten.org)
  • These promising results illustrate the potential to use this approach to develop new adsorbent materials capable of separating high-value chemical targets like alkenes from alkanes. (anl.gov)