Alkadienes: Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.Anatomy: A branch of biology dealing with the structure of organisms.Learning: Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.Computer-Assisted Instruction: A self-learning technique, usually online, involving interaction of the student with programmed instructional materials.Allyl CompoundsPropanols: Isomeric forms and derivatives of PROPANOL (C3H7OH).Palladium: 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.Samarium: Samarium. An element of the rare earth family of metals. It has the atomic symbol Sm, atomic number 62, and atomic weight 150.36. The oxide is used in the control rods of some nuclear reactors.Iridium: A metallic element with the atomic symbol Ir, atomic number 77, and atomic weight 192.22.Stereoisomerism: 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)Sweetening Agents: Substances that sweeten food, beverages, medications, etc., such as sugar, saccharine or other low-calorie synthetic products. (From Random House Unabridged Dictionary, 2d ed)Terminology as Topic: The terms, expressions, designations, or symbols used in a particular science, discipline, or specialized subject area.Carbonated Beverages: Drinkable liquids combined with or impregnated with carbon dioxide.Saccharin: Flavoring agent and non-nutritive sweetener.Aspartame: Flavoring agent sweeter than sugar, metabolized as PHENYLALANINE and ASPARTIC ACID.Taste: The ability to detect chemicals through gustatory receptors in the mouth, including those on the TONGUE; the PALATE; the PHARYNX; and the EPIGLOTTIS.HydrocarbonsBooksPolycyclic Hydrocarbons, Aromatic: A major group of unsaturated cyclic hydrocarbons containing two or more rings. The vast number of compounds of this important group, derived chiefly from petroleum and coal tar, are rather highly reactive and chemically versatile. The name is due to the strong and not unpleasant odor characteristic of most substances of this nature. (From Hawley's Condensed Chemical Dictionary, 12th ed, p96)Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Receptors, Aryl Hydrocarbon: Cytoplasmic proteins that bind certain aryl hydrocarbons, translocate to the nucleus, and activate transcription of particular DNA segments. AH receptors are identified by their high-affinity binding to several carcinogenic or teratogenic environmental chemicals including polycyclic aromatic hydrocarbons found in cigarette smoke and smog, heterocyclic amines found in cooked foods, and halogenated hydrocarbons including dioxins and polychlorinated biphenyls. No endogenous ligand has been identified, but an unknown natural messenger with a role in cell differentiation and development is suspected.Hydrocarbons, Aromatic: Organic compounds containing carbon and hydrogen in the form of an unsaturated, usually hexagonal ring structure. The compounds can be single ring, or double, triple, or multiple fused rings.Polycyclic Compounds: Compounds consisting of two or more fused ring structures.National Institute of General Medical Sciences (U.S.): Component of the NATIONAL INSTITUTES OF HEALTH. It conducts and supports basic biomedical research that is not targeted to specific diseases and funds studies on genes, proteins, and cells, as well as on fundamental processes like communication within and between cells and metabolism. It was established in 1962.Aldehydes: Organic compounds containing a carbonyl group in the form -CHO.NIH 3T3 Cells: A continuous cell line of high contact-inhibition established from NIH Swiss mouse embryo cultures. The cells are useful for DNA transfection and transformation studies. (From ATCC [Internet]. Virginia: American Type Culture Collection; c2002 [cited 2002 Sept 26]. Available from http://www.atcc.org/)United States Dept. of Health and Human Services: A cabinet department in the Executive Branch of the United States Government concerned with administering those agencies and offices having programs pertaining to health and human services.Aldehyde Dehydrogenase: An enzyme that oxidizes an aldehyde in the presence of NAD+ and water to an acid and NADH. This enzyme was formerly classified as EC 1.1.1.70.Gangliosidosis, GM1: An autosomal recessive neurodegenerative disorder caused by the absence or deficiency of BETA-GALACTOSIDASE. It is characterized by intralysosomal accumulation of G(M1) GANGLIOSIDE and oligosaccharides, primarily in neurons of the central nervous system. The infantile form is characterized by MUSCLE HYPOTONIA, poor psychomotor development, HIRSUTISM, hepatosplenomegaly, and facial abnormalities. The juvenile form features HYPERACUSIS; SEIZURES; and psychomotor retardation. The adult form features progressive DEMENTIA; ATAXIA; and MUSCLE SPASTICITY. (From Menkes, Textbook of Child Neurology, 5th ed, pp96-7)G(M1) Ganglioside: A specific monosialoganglioside that accumulates abnormally within the nervous system due to a deficiency of GM1-b-galactosidase, resulting in GM1 gangliosidosis.Receptors, Transferrin: Membrane glycoproteins found in high concentrations on iron-utilizing cells. They specifically bind iron-bearing transferrin, are endocytosed with its ligand and then returned to the cell surface where transferrin without its iron is released.Transferrin: An iron-binding beta1-globulin that is synthesized in the LIVER and secreted into the blood. It plays a central role in the transport of IRON throughout the circulation. A variety of transferrin isoforms exist in humans, including some that are considered markers for specific disease states.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Blood-Brain Barrier: Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Inventions: A novel composition, device, or process, independently conceived de novo or derived from a pre-existing model.Intellectual Property: Property, such as patents, trademarks, and copyright, that results from creative effort. The Patent and Copyright Clause (Art. 1, Sec. 8, cl. 8) of the United States Constitution provides for promoting the progress of science and useful arts by securing for limited times to authors and inventors, the exclusive right to their respective writings and discoveries. (From Black's Law Dictionary, 5th ed, p1014)Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Research: Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.Research Personnel: Those individuals engaged in research.Research Support as Topic: Financial support of research activities.Biomedical Research: Research that involves the application of the natural sciences, especially biology and physiology, to medicine.Research Design: A plan for collecting and utilizing data so that desired information can be obtained with sufficient precision or so that an hypothesis can be tested properly.Resins, Plant: Flammable, amorphous, vegetable products of secretion or disintegration, usually formed in special cavities of plants. They are generally insoluble in water and soluble in alcohol, carbon tetrachloride, ether, or volatile oils. They are fusible and have a conchoidal fracture. They are the oxidation or polymerization products of the terpenes, and are mixtures of aromatic acids and esters. Most are soft and sticky, but harden after exposure to cold. (From Grant & Hackh's Chemical Dictionary, 5th ed & Dorland, 28th ed)Copying Processes: Reproduction of data in a new location or other destination, leaving the source data unchanged, although the physical form of the result may differ from that of the source.PrintingWaxes: A plastic substance deposited by insects or obtained from plants. Waxes are esters of various fatty acids with higher, usually monohydric alcohols. The wax of pharmacy is principally yellow wax (beeswax), the material of which honeycomb is made. It consists chiefly of cerotic acid and myricin and is used in making ointments, cerates, etc. (Dorland, 27th ed)Food Coloring Agents: Natural or synthetic dyes used as coloring agents in processed foods.Carmine: Coloring matter from the insect Coccus cacti L. It is used in foods, pharmaceuticals, toiletries, etc., as a dye, and also has use as a microscopic stain and biological marker.Rubia: A plant genus of the family RUBIACEAE. The root is a source of red dyes (madder color and 1,2,4-trihydroxy-9,10-anthracenedione) and ANTHRAQUINONES.

Evidence of a cyclooxygenase-related prostaglandin synthesis in coral. The allene oxide pathway is not involved in prostaglandin biosynthesis. (1/176)

Certain corals are rich natural sources of prostaglandins, the metabolic origin of which has remained undefined. By analogy with the lipoxygenase/allene oxide synthase pathway to jasmonic acid in plants, the presence of (8R)-lipoxygenase and allene oxide synthase in the coral Plexaura homomalla suggested a potential metabolic route to prostaglandins (Brash, A. R., Baertshi, S. W., Ingram, C.D., and Harris, T. M. (1987) J. Biol. Chem. 262, 15829-15839). Other evidence, from the Arctic coral Gersemia fruticosa, has indicated a cyclooxygenase intermediate in the biosynthesis (Varvas, K., Koljak, R., Jarving, I., Pehk, T., and Samel, N. (1994) Tetrahedron Lett. 35, 8267-8270). In the present study, active preparations of G. fruticosa have been used to identify both types of arachidonic acid metabolism and specific inhibitors were used to establish the enzyme type involved in the prostaglandin biosynthesis. The synthesis of prostaglandins and (11R)-hydroxyeicosatetraenoic acid was inhibited by mammalian cyclooxygenase inhibitors (indomethacin, aspirin, and tolfenamic acid), while the formation of the products of the 8-lipoxygenase/allene oxide pathway was not affected or was increased. The specific cyclooxygenase-2 inhibitor, nimesulide, did not inhibit the synthesis of prostaglandins in coral. We conclude that coral uses two parallel routes for the initial oxidation of polyenoic acids: the cyclooxygenase route, which leads to optically active prostaglandins, and the lipoxygenase/allene oxide synthase metabolism, the role of which remains to be established. An enzyme related to mammalian cyclooxygenases is the key to prostaglandin synthesis in coral. Based on our inhibitor data, the catalytic site of this evolutionary early cyclooxygenase appears to differ significantly from both known mammalian cyclooxygenases.  (+info)

Biosynthesis of depudecin, a metabolite of Nimbya scirpicola. (2/176)

Feeding experiments of labeled acetates to Nimbya scirpicola proved the carbon origin of the straight-chain polyketide, depudecin. Differential hydrogen exchange of the 2H label originating from 2H labeled acetate along the polyketide chain occurred. In particular, the deuterium of an epoxide methine at C-3 was lost to a substantial extent in the formation of depudecin.  (+info)

Female Attacus atlas respond to pheromones of Antheraea polyphemus: a comparative electrophysiological and biochemical study. (3/176)

Female Attacus atlas respond electrophysiologically to both of the Antheraea polyphemus pheromone components (E,Z)-6,11-hexadecadienyl acetate and (E,Z)-6,11-hexadecadienal. Moreover, they possess a pheromone-binding protein (PBP) and general odorant-binding proteins (GOBPs), as well as a pheromone-degrading sensillar esterase and aldehyde oxidase enzymes. They show no electroantennogram responses to their own gland extract. In contrast, female A. polyphemus do not respond to their own or to A. atlas pheromone. Male A. atlas do not detect any of the A. polyphemus compounds but only the conspecific female gland extracts. Both male A. atlas and female A. polyphemus possess PBP and GOBP but lack the pheromone-degrading esterases of male Antheraea. The results indicate that the two species use quite distinct classes of chemicals as pheromones. In spite of this, the N-terminal amino acid sequences of the PBPs show homology of 68%.  (+info)

Using electroactive substrates to pattern the attachment of two different cell populations. (4/176)

This report describes the development of an electroactive mask that permits the patterning of two different cell populations to a single substrate. This mask is based on a self-assembled monolayer of alkanethiolates on gold that could be switched from a state that prevents the attachment of cells to a state that promotes the integrin-mediated attachment of cells. Monolayers were patterned into regions having this electroactive monolayer and a second set of regions that were adhesive. After Swiss 3T3 fibroblasts had attached to the adhesive regions of this substrate, the second set of regions was activated electrically to permit the attachment of a second population of fibroblast cells. This method provides a general strategy for patterning the attachment of multiple cell types and will be important for studying heterotypic cell-cell interactions.  (+info)

Activation and inhibition of the transduction process in silkmoth olfactory receptor neurons. (5/176)

Electrophysiological responses of olfactory receptor neurons in both male and female silkmoths (Bombyx mori) were investigated. In both sexes, the G-protein activator sodium fluoride and 1,2-dioctanoyl-sn-glycerol, a membrane-permeable analog of the protein kinase C activator diacylglycerol, elicited nerve impulse responses similar to those elicited by weak continuous stimulation with odorants. Therefore, G(q)-proteins and diacylglycerol-activated ion channels seem to be involved in the transduction process in both pheromone-sensitive neurons in males and general odorant-sensitive neurons in females. Decyl-thio-trifluoro-propanone is known to inhibit electrophysiological responses of male moths to pheromones, but has no effect in females. Application of this inhibitor reduced the frequency, but not the amplitude of elementary receptor potentials. It had no inhibitory effect on nerve impulse responses elicited by sodium fluoride or 1,2-dioctanoyl-sn-glycerol. This supports the idea that decyl-thio-trifluoro-propanone acts on a prior step of the transduction cascade, e.g. on the pheromone receptor molecules. General odorants, such as (+/-)-linalool and 1-heptanol, excite olfactory receptor neurons in females, but inhibit the pheromone-sensitive neurons in males. Both (+/-)-linalool and 1-heptanol inhibited the responses of male neurons elicited by sodium fluoride or 1,2-dioctanoyl-sn-glycerol. (+/-)-Linalool reduced the amplitude of elementary receptor potentials. In contrast to decyl-thio-trifluoro-propanone, (+/-)-linalool and 1-heptanol seem to interfere with later processes of the transduction cascade, possibly the opening of ion channels.  (+info)

A novel push-pull Diels-Alder diene: reactions of 4-alkoxy- or 4-phenylsulfenyl-5-chalcogene-substituted 1-phenylpenta-2,4-dien-1-one with electron-deficient dienophiles. (6/176)

5-(phenylselenenyl)- and 5-(phenylsulfenyl)-4-ethoxy-1-phenyl-2,4-pentadien-1-ones (2) and (3) underwent [4+2] cycloaddition with N-methyl and N-phenylmaleimides and successive isomerization to give the 7-benzoyl-3a,4,5,7a-tetrahydro-1H-isoindole-1,3(2H)-diones 5, 8 and 9 in good yields. The 4-ethoxy group on the 2,4-pentadien-1-one was found to be effective to facilitate the cycloaddition with dienophiles. We also performed other [4+2] cycloadditions of 2,4-pentadien-1-ones with DMAD or naphthoquinone.  (+info)

Adaptation in pheromone-sensitive trichoid sensilla of the hawkmoth Manduca sexta. (7/176)

In extracellular tip recordings from long trichoid sensilla of male Manduca sexta moths, we studied dose-response relationships in response to bombykal stimuli of two different durations in the adapted and the non-adapted state. Bombykal-responsive cells could be distinguished from non-bombykal-sensitive cells in each trichoid sensillum because the bombykal-responsive cell always generated the action potentials of larger initial amplitude. The bombykal cell, which was recorded at a defined location within a distal flagellar annulus, can resolve at least four log(10)-units of pheromone concentrations but is apparently unable to encode all stimulus durations tested. Parameters of the amplitude-modulated sensillar potential and the frequency-modulated action potential responses were examined in different states of adaptation. Evidence is presented for the existence of several mechanisms of adaptation, which affect distinct steps of the transduction cascade. After adapting pheromone stimuli, the sensillar potential rises to a lower amplitude and declines faster compared with the non-adapted response. In addition, the frequency of the adapted action potential response is reduced. Only the time of rise of the sensillar potential is differentially affected by adapting pheromone stimuli of different duration. The time of rise does not increase after short, but only after long, adapting stimuli. Both short and long adapting stimuli shift the dose-response curves of the sensillar potential amplitude, as well as the initial slope of its rising phase, to higher stimulus concentrations by approximately one log(10)-unit. The shift in the dose-response curve of the action potential response is larger than for the sensillar potential response, suggesting that an additional adaptation mechanism acts at the level of action potential generation. Furthermore, a faster decline of the sensillar potential after short and long adapting stimuli suggests that the resting potential of the olfactory receptor neuron is stabilized.  (+info)

Synthesis and characterization of hexadecadienyl compounds with a conjugated diene system, sex pheromone of the persimmon fruit moth and related compounds. (8/176)

Hexadecadien-1-ol and the derivatives (acetate and aldehyde) with a conjugated diene system have recently been identified from a pheromone gland extract of the persimmon fruit moth (Stathmopoda masinissa), a pest insect of persimmon fruits distributed in East Asia. The alcohol and acetate showed their base peaks at m/z 79 in a GC-MS analysis by electron impact ionization, but the aldehyde produced a unique base peak at m/z 84, suggesting a 4,6-diene structure. To confirm this inference, four geometrical isomers of each 4,6-hexadecadienyl compound were synthesized by two different routes in which one of two double bonds was furnished in a highly stereoselective manner. Separation of the two isomers synthesized together by each route was facilely accomplished by preparative HPLC. Their mass spectra coincided well with those of natural components, indicating that they were available for use as authentic standards for determining the configuration of the natural pheromone. Furthermore, other hexadecadienyl compounds, including the conjugated diene system between the 3- and 10-positions, were synthesized to accumulate the spectral data of pheromone candidates. 5,7-Hexadecadienal interestingly showed the base peak at m/z 80; meanwhile, the base peaks of its alcohol and acetate were detected at m/z 79 like the corresponding 4,6-dienes. The base peaks of all 6,8-, 7,9-, and 8,10-dienes universally appeared at m/z 67 like 9,11-, 10,12-, and 13,15-dienes, the spectra of which have already been published. Although 3,5-hexadecadienal was not prepared, base peaks at m/z 67 and 79 were recorded for the alcohol and acetate, respectively.  (+info)

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.
Allcosmeticsource.com Piperine 99%(CAS#94-62-2) 20MG/vial, FREE SHIPPING [PTC-RP0-1561]- Piperine 99%(CAS#94-62-2) 20MG/vial, FREE SHIPPING CAS No.: 94-62-2 Specifications Formula:C17H19NO3 Molecular Weight:285.37 Deleted CAS:147030-08-8 Synonyms:1-[(2E,4E)-5-(1,3-benzodioxol-5-yl)penta-2,4-dienoyl]piperidine;FEMA No. 2909;Bioperine;Piperine (aliphatic);Piperidine, 1-((2E,4E)-5-(1,3-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl)-;1-Piperoyl-piperidine;(E,E)-1-[5-(1,3-Benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]-piperidine;Piperidine,1-[(2E,4E)-5-(1,3-benzodioxol-5- yl)-1-oxo-2,4-pentadienyl]-;N-[(E,E)-Piperoyl]piperidine;Piperidine, 1-(5-(1,3-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl)-, (E,E)- (9CI); EINECS:202-348-0 Density:1.211 g/cm3 Melting Point:131-135 °C(lit.) Boiling Point:498.5 °C at 760 mmHg Flash Point:255.3 °C Solubility:40 mg/L (18 °C) inwater Appearance:slightly yellow powder Hazard Symbols:Xn Risk Codes:21/22 Safety:36/37 Details AvailableForms:Powder
This thesis is focused on two main areas of organic synthesis, palladium-catalyzed functionalization of alkenes and allylic alcohols, as well as development of new allylboration reactions.. We have developed a palladium-catalyzed selective allylic trifluoroacetoxylation reaction based on C−H functionalization. Allylic trifluoroacetates were synthesized from functionalized olefins under oxidative conditions. The reactions proceed under mild conditions with a high level of diastereoselectivity. Mechanistic studies of the allylic C−H trifluoroacetoxylation indicate that the reaction proceeds via (η3-allyl)palladium(IV) intermediate.. Palladium-catalyzed regio- and stereoselective synthesis of allylboronic acids from allylic alcohols has been demonstrated. Diboronic acid B2(OH)4 was used as the boron source in this process.. The reactivity of the allylboronic acids were studied in three types of allylboration reactions: allylboration of ketones, imines and acyl hydrazones. All three processes ...
Phthalides by rhodium-catalyzed ketone hydroacylation.: Phthalides are biologically relevant five-membered lactones found in herbs, fruits, and vegetables. Here
The antineoplastic properties of α,β-unsaturated ketones, such as curcumin and related analogs, have been investigated for a number of years. Due to the high light sensitivity and the low bioavailability of curcumin and its analogs, there was a need to modify its structural features for clinical usage as a chemotherapeutic candidate. The emphasis on synthetic curcumin analogs which have the 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore (Figure 2-1, page 32) and its importance for eliciting antineoplastic activity was made from this laboratory. It was proven that one way these agents exert their activity is through a thiol-alkylating mechanism. In order to increase the cytotoxic activity of these candidate agents, three target compounds containing the 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore were designed by incorporating potential auxiliary binder groups (Figure 2-2, page 33). The auxiliary binders may display antineoplastic properties, or they may act only to enhance the bonding at the ...
. 0 onjugated Systems hapter 0 onjugation in Alkadienes and Allylic Systems onjugated systems are those in which a π-bond is connected or conjugated (from the Latin conjugare which means to link r yoke
A page within the free MCAT Learning Program produced by Wisebridge Learning Systems. The topic under discussion here is Alkadienes, allylic systems, and pigments - The WikiPremed MCAT Course
A facile Pd-catalyzed intramolecular aminofluorination reaction of allylic sulfamides was developed that can be used to prepare fluorinated 1,3-diamine derivatives. Acetic acid was essential for regulation to give the major 6-endo cyclization products ...
1)Su, Y., Petersen, J. L.,Gregg, T. L.,Shi, X.*, "Ambient 1,2,3-Triazole Ring Opening through Intermolecular Radical Addition to Vinyl-Triazole." Org. Lett., 2015, 17, 1208-1211.; 2)Dong, B.‡, Su, Y.‡, Ye, X., Petersen, J. L., Shi, X.*, "Synthesis and Characterization of Fluorescent-Active Triazole-Gold Complexes." Sci. China Chem., 2015, 58, 1-4.; 3)Su, Y., Lu, M., Dong, B., Chen, H.*, Shi, X.* "Silver Catalyzed Alkyne Activation: the Surprising Ligand Effect" Adv. Syn. Cat., 2014, 356, 692-696.; 4)Su, Y., Zhang, Y., Akhmedov, N. G., Petersen, J. L., Shi, X.*, "Ambient Intermolecular [2 + 2] Cycloaddition: An Example of Carbophilicity and Oxophilicity Competition in Au/Ag Catalysis." Org. Lett., 2014, 16, 2478-2481.; 5)Xi, Y.‡, Su, Y.‡, Yu, Z., Dong, B., McClain, E. J., Yu, L.*, Shi, X.*, "Chemoselective Carbophilic Addition of α-Diazoesters through Ligand-Controlled Gold Catalysis." Angew. Chem. Int. Ed., 2014, 53, 9817-9821; 6) Su, Y.‡, Sun, X.‡, Wu, G., Jiao, ...
摘要. Merging photoredox catalysis and chiral primary amine catalysis enables the coupling of phenacyl radicals and enamine carbonyls to generate acyclic all-carbon quaternary centers with excellent enantioselectivity under visible light irradiation. See Luo and co-workers, p 14642. ...
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
A cascade reaction, also known as a domino reaction or tandem reaction, is a chemical process that comprises at least two consecutive reactions such that each subsequent reaction occurs only in virtue of the chemical functionality formed in the previous step. In cascade reactions, isolation of intermediates is not required, as each reaction composing the sequence occurs spontaneously. In the strictest definition of the term, the reaction conditions do not change among the consecutive steps of a cascade and no new reagents are added after the initial step. By contrast, one-pot procedures similarly allow at least two reactions to be carried out consecutively without any isolation of intermediates, but do not preclude the addition of new reagents or the change of conditions after the first reaction. Thus, any cascade reaction is also a one-pot procedure, while the reverse does not hold true. Although often composed solely of intramolecular transformations, cascade reactions can also occur ...
Lower download a clinical application of the gene receives lymphoma of last climates in running support, Long-term treatment doctor, and saving the number of breast. 43; milk laboratory and insecticides. 43; download a clinical application of bions concepts volume 1 dreaming transformation containment and world and further B6 to infertile and young Effects are categorized to collect Gestational for fibrosis of RA( 75). 02013; 10 possibility participating is a Chemotherapy-induced health, abundantly focusing RA( 74). RA treatments very considered to synthetic download a clinical application of bions concepts volume 1 dreaming transformation, although the oranges d complementary of portions in Absolute Atherosclerosis( 54). 02013; 10 factors with dental murine buzz of effect cancer, dendrorhous times, tissue, gel, and homocysteine of results; psoriasis favors from patients, chemicals, and cc; and a various colonic relation reserve obtained by 1 challenge of a spinach existence again applied to ...
Ligand-Controlled Product Selectivity in Electrochemical Carbon Dioxide Reduction Using Manganese Bipyridine Catalysts. / Rønne, Magnus H.; Cho, Dasol; Madsen, Monica R.; Jakobsen, Joakim B.; Eom, Seunghwan; Escoudé, Émile; Hammershøj, Hans Christian D.; Nielsen, Dennis U.; Pedersen, Steen U.; Baik, Mu Hyun; Skrydstrup, Troels; Daasbjerg, Kim.. I: Journal of the American Chemical Society, Bind 142, Nr. 9, 03.2020, s. 4265-4275.. Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review ...
An efficient procedure for the syntheses of pyrazolo[1,5-a]pyrimidines through reactions of 1,2-allenic ketones with aminopyrazoles under extremely mild conditions without using any catalyst or promoter has been developed. The reactions showed excellent regio-selectivity with all the allenic ketone substrate
Photochromic diaryl-2H-naphthopyran structures, which dye photochromically well at room temperature, lighten up quickly when incorporated into ophthalmic lenses, possess longevity, and due to their spacial structures, have a reduced tendency of the molecules to migrate in plastics.
A free platform for explaining your research in plain language, and managing how you communicate around it - so you can understand how best to increase its impact.
see article for more reactions. Abstract. Allenyl carbinol esters isomerize to an E,Z mixture of the corresponding dienes in the presence of a gold catalyst. In a subsequent reaction with Selectfluor, this mixture can be converted to monofluoroalkyl α,β-unsaturated ketones with exclusive E selectivity in high yields.. ...
In this study, pericolic lymph nodes from individuals with an observed immune response to the central domain of p53 were used to construct recombinant antibody libraries. From these libraries, we were able to isolate a Fab with specificity for the central domain of p53. We subsequently showed that this antibody bound the denatured form of whole p53 and also recognized an epitope that was close to, or perhaps overlapped, the binding site of the murine antibody DO11 (181-190). This is the first report of the isolation of a human antibody to the central domain of p53, and highlights the ability of antibody phage display to isolate antibodies with novel reactivity to p53.. Approximately 10% of individuals in this study had serum antibodies to the central domain of p53, a frequency that is almost twice that found in previous studies of cancer patients (12 , 16 , 26) . There are a number of methodological differences in published studies that may account for this discrepancy. These include the type of ...
Session Objectives: Recognize the NHCS PBS-PSM/RtI Unified Plan Identify NHCS current Knowledge Creation Enterprises Critique the NHCS Unified Plan and Knowledge Creation Enterprises BT
2.4.2015 г. 1 Лекция 5 Алкадиени-класификация, строеж, изомерия, химични свойства, полимеризация на диени Органична химия Пантелей Денев Струпани Спрегнати Изо…
Preventing Chronic Cluster Headaches - Cluster headache treatment can help you feel better. Learn great information on treating your cluster headaches from HowStuffWorks.
Revised criteria from the third edition of the International Classification of Headache Disorders (ICHD-3), can differentiate between chronic cluster headache (CCH) and episodic cluster headache (ECH) and may increase the number of CCH diagnoses.
by Reed Migraine Centers , Apr 21, 2018. Reed Migraine Centers - Founders and Inventors of the Omega Procedure , Reed Procedure , 4-Lead Procedure , » chronic cluster headache » Page 2 Click on the image to view the full file. FREE WEBINAR Learn more about the Reed and Omega migraine procedure treatment ...
Current evidence on the efficacy of implantation of a sphenopalatine ganglion stimulation device for chronic cluster headache, in the short term (up to 2 months), is adequate. With regard to safety, a variety of complications have been documented, most of which occur early and resolve; surgical revision of the implanted system is sometimes needed. Therefore, this procedure should only be used with special arrangements for clinical governance, consent and audit or research. ...
Herein, a wide range of mono- and di-arylated products were efficiently prepared from C-N coupling of 2-halobenzothiazoles and primary aromatic amines, and representative compounds 3b and 4b were further confirmed by X-ray crystallography. It was noteworthy that the di-arylated products, denoted as di(benzothiazoly
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
In the palladium-catalyzed cyclization of allenic allylic esters using Pd(dba)2 as catalyst, it was shown that the allene acts as a carbon nucleophile. Intermediates were isolated and stereochemical studies established that the double bond of the allene has attacked the (π-allyl)palladium intermediate on the face opposite to that of palladium.. ...
A one-pot protocol for the synthesis of triazole-annulated polyheterocycles via metal-catalyzed coupling of internal 1,4-disubstituted 1,3-diynes and organic azides has been described. The mechanistic rationale for the reaction suggests tandem cycliz
If youve had cluster headaches for a long time and other treatments havent worked, surgery to implant a stimulation device may be recommended.. Under general anaesthetic, a small electrical device is implanted in a cavity in the side of your face. It emits electrical currents which stimulate an area of the parasympathetic nervous system thought to be associated with cluster headaches.. When you get a headache, you activate the device (up to a pre-determined maximum dose) by placing a handheld unit on your cheek over the place where the device is located.. As with TVNS, the aim of treatment is to relieve pain and reduce the frequency of cluster headache attacks.. NICE have recommended that the treatment is safe for short-term use (up to two months) under close specialist supervision.. For more information, read the NICE guidance about implantation of a sphenopalatine ganglion stimulation device for chronic cluster headache. ...
Hoffmann, R.; Tantillo, D. J. Angew. Chem. Int. Ed. 2003, 42, 5877-5882: Breaking Down Barriers: The Liaison Between Sigmatropic Shifts, Electrocyclic Reactions and 3-Center Cations. Ponec, R.; Bultinck, P.; Van Damme, S.; Carbo, R.; Tantillo, D. J. Theor. Chem. Acc. 2005, 113, 205-211: Geometric and Electronic Similarities between Transition Structures for Electrocyclizations and Sigmatropic Hydrogen Shifts. Tantillo, D. J. Annu. Rep. Prog. Chem., Sect. B 2006, 102, 269-289: Reaction Mechanisms. Part (ii) Pericyclic Reactions. Tantillo, D. J.; Lee, J. K. Annu. Rep. Prog. Chem., Sect. B 2007, 103, 272-293: Reaction Mechanisms. Pericyclic Reactions. Lee, J. K.; Tantillo, D. J. Annu. Rep. Prog. Chem., Sect. B 2008, 104, 260-283: Reaction Mechanisms. Pericyclic Reactions. Nouri, D. H.; Tantillo, D. J. Tetrahedron 2008, 64, 5672-5679: Sigmatropic Shifts and Cycloadditions on Neutral, Cationic, and Anionic Pentadienyl + Butadiene Potential Energy Surfaces. Tantillo, D. J. Angew. Chem. ...
It all started in 1995 when I was traveling the country (US) advocating street style self defense. I produced a self-defense video teaching people how to use ordinary items and dirty tricks to defend themselves from criminal assaults. One of my gimmicks for getting publicity was to be sprayed with real police pepper spray. I ended up on the Oprah Winfrey show and I taught Oprah how to use self-defense pepper spray. After that show, I was bombarded with appearance requests from all over the country. Suddenly I was getting sprayed with pepper spray for small tv stations around the country while promoting my self defense videos. I had suffered from chronic cluster headaches and allergy problems for 20 years, but I never had a headache attack during one of my self defense demos. Then one day I was about to be sprayed by a television reporter at a local FOX News affiliate, and minutes before I had to go on the air I was hit with a cluster attack. Since the show had to go on, I let the reporter spray ...
For more course tutorials visit\nwww.uophelp.com\n\nHCS 446 Week 1 Discussion Question 1\nHCS 446 Week 1 Discussion Question 2\nHCS 446 Week 1 Individual Assignment Facility Planning - Part I\nHCS 446 Week 2 Discussion Question 1 \nHCS 446 Week 2 Discussion Question 2 \nHCS 446 Week 2 Team Assignment Environmental Impact Outline\nHCS 446 Week 3 Discussion Question 1 \nHCS 446 Week 3 Discussion Question 2\nHCS 446 Week 3 Individual Assignment Facility Planning - Part II\nHCS 446 Week 4 Discussion Question 1\nHCS 446 Week 4 Discussion Question 2\nHCS 446 Week 4 Team Assignment Facility Planning - Part III\nHCS 446 Week 5 Discussion Question 1\nHCS 446 Week 5 Discussion Question 2\nHCS 446 Week 5 Team Assignment Environmental Impact Presentation\n\n\n Slideshow 7237938 by bagyanagar3
Ruthenium-Catalyzed Alkene-Alkyne Coupling of Disubstituted Olefins: Application to the Stereoselective Synthesis of Trisubstituted Enecarbamates
Researchers: Andrew Babiskin, Travis Bayer, Chase Beisel, Stephanie Culler, Katie Galloway, Kevin Hoff, Maung Nyan Win We are exploring the design strategies for constructing molecular switches that act in vivo as both biosensors and ligand-controlled regulators of gene expression in bacteria, yeast, and mammalian cell culture. Much of our effort is focused on the design of nucleic acid-based molecular sensors, although the design of some protein-based sensors is being explored as well. In the area of trans-acting molecular switches, we are exploring the design of sensors that act through diverse gene regulation mechanisms such as the RNA interference (RNAi) pathway, ribozyme-based cleavage, and the antisense pathway. In the area of cis-acting molecular switches, we are exploring the design of sensors that act through regulatory mechanisms such as alternative splicing, RNase III cleavage, ribozyme-based cleavage, and internal ribosome entry site (IRES) activity. In order to effectively monitor ...
Eric Jacobsen and co-workers published in JACS on a hydroamination using a thiourea catalyst. Its refreshing to see a hydroamination without a transition metal. JACS paper
Matthias Beller and co-workers have reported in JACS on a ligand controlled regioselectivitiy switching of an alkoxycarbonylation of an allene substrate. JACS paper
Get 24/7 Addition Of Halogen To Dienes Assignment Help / Homework Help Online from experts on Transtutors.com. ✓20% discount ✓100% Cashback* ✓4374+ Addition Of Halogen To Dienes Experts. Ask Now ! Get 100% error-free solutions at affordable prices
ALL ABOUT DRUGS BY DR ANTHONY MELVIN CRASTO, WORLD DRUG TRACKER HELPING MILLIONS, MILLION HITS ON GOOGLE..............................................
Highly branch-selective, carbonyl-directed hydroarylations of monosubstituted alkenes are described. The chemistry relies upon a cationic Ir(I) catalyst modified with an electron deficient, wide bite angle bisphosphine ligand. This work provides a regioisomeric alternative to the Murai hydroarylation protocol.. Full details in the University publications repository. ...
Development of anionic cascade reactions and other novel reactions of conjugated, acetylenic and allenic esters and thioesters. Toward the synthesis of biologically active ...
The Nazarov cyclization is a common synthetic tool in the synthesis of cyclopentenone rings. The reaction is characterized by a divinyl ketone starting reagent that undergoes a 4π-electron electrocyclization after addition of a Lewis/Brønsted acid; forming the cyclopentadienyl cation that undergoes cyclization. An extension of this methodology involves using a divinyl imine starting reagent. This cyclization is less favoured due to the electron donating ability of the nitrogen atom, causing the pentadienyl cation to be relatively stable and unwilling to undergo cyclization. To improve this cyclization, the imine is replaced with the electron withdrawing nitronate functionality. It is hypothesized that by doing so the addition of an acid will form the cyclopentadienyl cation that will readily undergo Nazarov cyclization. The synthesis of an aryl vinyl silyl nitronate was optimized and the compound was tested with a number of different acid catalysts to determine if the nitronate Nazarov ...
en] Background Drug-resistant chronic duster headache (drCCH) is a devastating disorder for which various destructive procedures have been tried unsuccessfully. Occipital nerve stimulation (ONS) is a new, safe strategy for intractable headaches. We undertook a prospective pilot trial of ONS in drCCH to assess clinical efficacy and pain perception. Methods Eight patients with drCCH had a suboccipital neurostimulator implanted on the side of the headache and were asked to record details of frequency, intensity, and symptomatic treatment for their attacks in a diary before and after Continuous ONS. To detect changes in cephalic and extracephalic pain processing we measured electrical and pressure pain thresholds and the nociceptive blink reflex. Findings Two patients were pain free after a follow-up of 16 and 22 months; one of them still had occasional autonomic attacks. Three patients had around a 90% reduction in attack frequency. Two patients, one of whom had had the implant for only 3 months, ...
see article for more reactions. Abstract. A highly efficient oxidation of propargylic alcohols to ynones is catalyzed by copper nanoparticles (Cu Nps) with TBHP or air as oxidants. With bipyridine as the ligand, the reaction was accelerated significantly and led in good to excellent yields to a variety of propargylic alcohols.. ...
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
ESI Induced Gas-Phase Nazarov Cyclization of (2E)-3-(2-Methoxyphenyl)-1-(thiophen-2-yl)-prop-2-en-1-one and its Oxygen Analogue ...
TY - JOUR. T1 - New synthesis of acylferrocene by hydroiminoacylation of the terminal olefin with ferrocenecarboxaldimine and application to polymer-supported acylferrocene. AU - Chul-Ho, Jun. AU - Jung-Bu, Kang. AU - Jin-Yong, Kim. PY - 1993/10/5. Y1 - 1993/10/5. N2 - Acylferrocenes were synthesized by hydroiminoacylation of the ω-olefins 1-pentene (3a), vinylferrocene (3b) and but-3-enylferrocene (3c), with the ferrocenecarboxaldimine 2, prepared from ferrocenecarboxaldehyde (1) and 2-amino-3-picoline, under the action of Wilkinsons catalyst, followed by hydrolysis of the corresponding ketimines (5a, 5b and 5c). This hydroiminoacylation was used to incorporate the ferrocenyl group into phenyl-terminated poly-butadiene (PTPB, consisting of 27% vinyl and 73% internal olefin group). 74% hydroacylation of the vinyl group in 7 was accomplished in the first catalytic reaction and in 10 the second hydroacylation completed the conversion of the vinyl group into acylferrocene.. AB - Acylferrocenes ...
10. A method for producing a conjugated diene polymer, comprising steps A and B:step A: polymerizing monomers comprising a conjugated diene and a vinyl compound of formula (VI) in a hydrocarbon solvent in the presence of an alkali metal catalyst to produce a polymer having an alkali metal originating from the catalyst at least one terminus of a polymer chain comprising a conjugated diene-based monomer unit and a monomer unit based on the vinyl compound of formula (VI), ##STR00032## wherein X4, X5, and X6 independently denote a group of formula (VIa), a hydrocarbyl group, or a substituted hydrocarbyl group, and at least one of X4, X5, and X6 is a group of formula (VIa), ##STR00033## wherein R3 and R4 independently denote a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1 to 6 carbon atoms, a silyl group, or a substituted silyl group, and R3 and R4 may be bonded so as to form, together with the nitrogen atom, a ring structure, andstep B: reacting the resulting ...
Dihalocarbenes were added to allenes to form dihalo-methylene- cyclopropanes which were then converted by the n-butyl lithium method to cumulenes. Both dichloro- and dibroraocarbenes were found to add to the allene double bond with the highest number of alkyl substituents. Propargyl alkenylmalonates were prepared in good yields and pyrolised under carefully controlled conditions to give allenic alkylidenemalonates in fair yields by Cope Rearrangement, but gave fission products under more extreme conditions. The position of the alkyl substituents on the alkenylmalonate group seemed to influence the ease of the rearrangement. Cyclopropanes were prepared in good yields from different types of x, b-unsaturated esters by the dimethylsulphozonium methylide reaction in dimethyl sulphoxide and dimethylformamide solvents. An Allentc ester, on the other hand, gave an unstable complex postulated as dimethylsulphoxonium 3-ethozycarbonyl 2-methylallylide. The syntheses of the only two naturally-occurring ...
We have investigated the relationship between sexual isolation and DNA sequence divergence in the transformation (at locus rpoB) of a naturally competent strain of Bacillus subtilis. Using both genomic DNA and a PCR-amplified segment of gene rpoB as donor, we found that the extent of sexual isolation at locus rpoB was closely predicted, over three orders of magnitude, as a log-linear function of sequence divergence at that locus. Because sexual isolation between a recipient and any potential donor may be determined as a general mathematical function of sequence divergence, transformation is perhaps the only sexual system, in either the prokaryotic or the eukaryotic world, in which sexual isolation can be predicted for a pair of species without having to perform the cross. These observations suggest the possibility of a general approach to the indirect prediction of sexual isolation in bacteria recombining principally by natural transformation. ...
wherein X means an alkenyl group C2-C7 substituted by two methyls, nitro-radical mono-substituted thienyl, unsubstituted quinolinyl, unsubstituted indolyl, unsubstituted pyridazinyl, unsubstituted piperazinyl, C1-C6-alkyl disubstituted piperazinyl, unsubstituted piperidinyl, unsubstituted pyrazinyl, unsubstituted imidazolyl, unsubstituted pyrimidinyl, phenyl monosubstituted pyrimidinyl, pyrimidinyl disubstituted by an amine radical and a radical specified in a group containing -F, -Cl, -Br or -I, hydroxyl trisubstituted phenyl, methoxy-radical trisubstituted phenyl, hydroxyl and methoxy-radical disubstituted phenyl, pyrazolyl disubstituted by a radical specified in a group containing a C1-C6-alkyl, and by a radical specified in a group containing -F, -C1, -Br or -I; Y means aminophenyl monosubstituted by a radical of -F, -O, -Br or -I phenyl, hydroxyethyl disubstituted by hydroxymethyl or C1-C6-alkyl and phenyl monosubstituted by a nitro group, an amino group or a halogen atom; Y also means ...
Antennae of the tobacco hornworm moths Manduca sexta contain an aldehyde oxidase (AOX) that oxidizes aldehydes to carboxylic acids. The enzyme, which is distinguishable from aldehyde-oxidizing activities in other tissues, is secreted into the receptor lymph that bathes the primary olfactory dendrites. First detectable about 3 d before eclosion, AOX levels increase through the first day after eclosion. This parallels the development of the antennal responsiveness to bombykal (a male attractant aldehydic pheromone produced by female M. sexta) and trans-2-hexenal (an aldehyde commonly found in leaves). The AOX is about 60% more abundant in antennae of males than in antennae of females. The antennal AOX is a dimer with Mr of 295 kDa and is capable of oxidizing a variety of aldehydes. Of all aldehydes examined, the pheromone bombykal was the best substrate with an apparent Km of 5 microM, whereas the next best substrate, benzaldehyde, had an apparent Km of 255 microM. Using kinetic parameters ...
In palladium-catalysed methoxycarbonylation of technical propyne, the presence of propadiene poisons the hemilabile Pd(P,N) catalyst. According to density functional theory calculations (B3PW91-D3/PCM level), a highly stable π-allyl intermediate is the reason for this catalyst poisoning. Predicted regioselectivities suggest that at least 11% of propadiene should yield this allyl intermediate, where the reaction gets stalled under the turnover conditions due to an insurmountable methanolysis barrier of 25.8 kcal mol-1. Results obtained for different ligands and substrates are consistent with the available experimental data. A new ligand, (6-Cl-3-Me-Py)PPh2, is proposed, which is predicted to efficiently control the branched/linear selectivity, avoiding rapid poisoning (with only 0.2% of propadiene being trapped as Pd allyl complex), and to tremendously increase the catalytic activity by decreasing the overall barrier to 9.1 kcal mol-1 ...
A series of 2-arylquinazolines have been synthesized in moderate to excellent yields by one-pot tandem reaction of (2-aminophenyl)methanols, aldehydes and ceric ammonium nitrate (CAN). The utility of this transformation was demonstrated by its compatibility with a wide range of functional groups. Thus, the method represents a simple and practical procedure to access 2-arylquinazolines.
We demonstrate an efficient protocol for the chemoselective hydroboration of organic nitriles with pinacolborane (HBpin) and catecholborane (HBcat) using aluminum alkyl complex [κ2‐{2‐F‐C6H4NP(Se)Ph2}2Al‐(Me)] as a pre‐catalyst to afford diboryl amines under solvent‐free and mild conditions (60°C) in high yield. The aluminum complex was prepared by the reaction of [2‐F‐C6H4NHP(Se)Ph2] and trimethylaluminum in toluene. The solid‐state structure of Al complex is established. Nitriles with a wide array of electron‐withdrawing and electron‐donating functional groups were easily converted to the desired products through the formation of aluminum hydride as an active species. A kinetic study of the catalytic reaction is also reported.. ...
A series of hexasubstituted butadienes of type A was prepared representing (E,E)-1,2,3,4-tetrachloro-5-methoxy-1,3-pentadienes (7) substituted by different terminal residues R. 1H n.m.r. data of diastereotopic methylene protons served to determine the barriers of rotation around the central CC single bond of the butadienes A. The considerable dependence of this barrier (ΔGmath image = 12.8-21.1 kcal/mole) upon the size of the terminal substituents R ist discussed in terms of a buttressing effect of these groups. ...
Piperylene concentrate is a complex mixture of 5-carbon unsaturates. The major components are trans-1,3-pentadiene and cyclopentene. The object of this work is to form a product high in cyclopentene and a product high in the pentadienes, through ...
Ringerweiterung von NHCs! Die Reaktion N-heterocyclischer Carbene (NHCs) mit Hydrosilanen Ph4−nSiHn (n=1, 2, 3) führt zu einem vollständigen Aufbrechen des Heterocyclus unter Silyleninsertion in eine der C-N-Bindungen des Carbens (siehe Schema; R=Alkyl, Aryl). ...
The micro organism proliferation following this new production way is twice more efficient (both in terms of speed of proliferation and of population per volume) than classical sol-gel ...
Examples: (equiv (* x y) 3) -- replace (* x y) by 3 everywhere inside the current subterm, if their equality is among the top-level hypotheses or the governors (equiv x t iff) -- replace x by t everywhere inside the current subterm, where only propositional equivalence needs to be maintained at each occurrence of x General form: (equiv old new &optional relation ...
Еремеев А.В.; Солодин И.В.; Лиепиньш Э.Э.; Костяновский Р.Г. Исследование методов синтеза азиридинов и азиринов на основе этил-beta,beta-бис(трифторметил)акрилата = Investigation of methods for the synthesis of aziridines and azirines on the basis of ethyl-beta,beta-bis(trifluoromethyl) acrilate. Химия гетероцикл.соед. 1984(7), 917-921; Chem.Heterocycl. Comp. (Engl. Ed.). 1984, 20(7), 744-748 ...
Dear collegues, The procedure was made by Dr. Nazarov Alexei in Archangelsk. Clinical case description: female, 48 years old, stent was placed after the argon-plasma coagulation of the tumor. ...
Communications DOI: 10.1002/anie.201100706 Organocatalysis Cinchona Alkaloid Amide Catalyzed Enantioselective Formal [2+2] Cycloadditions of Allenoates and Imines: Synthesis of 2,4-Disubstituted Azetidines** Jean-Baptiste Denis, Graldine Masson,* Pascal Retailleau, and Jieping Zhu* Chiral azetidines[1] represent an important class of fourmembered nitrogen heterocycles that have a wide range of synthetic applications,[1-3] remarkable biological activities,[1, 4] and are prevalent in natural products.[1, 5] However, in contrast to the homologous small-ring saturated nitrogen heterocycles such as aziridines, pyrrolidines, and piperidines, the synthetic approaches to enantiomerically enriched azetidines are few in number and are generally multistep processes.[1, 6, 7] Among the different synthetic routes, the formal [2+2] cycloaddition[8] is certainly one of the most powerful methods for the construction of the strained four-membered ring. However, only a few catalytic enantioselective methods have ...
Since the discovery of the Grignard reaction more than a century ago, carbonyl addition mediated by premetalated reagents has played a central role in synthetic chemistry. Metal-catalyzed reductive coupling of π-unsaturated reactants with carbonyl compounds has emerged as an alternative to classical carbonyl addition. Although such processes bypass stoichiometric organometallic reagents and the issues of safety, selectivity, and waste associated with their use, in many cases the requisite terminal reductants are just as problematic as the organometallic reagents they replace. Catalytic reductive coupling via hydrogenation or transfer hydrogenation represents a more ideal strategy for carbonyl addition as relatively safe, inexpensive reductants with low molecular weights may be used (H2 or 2-propanol). Carbonyl addition via hydrogen autotransfer is most ideal. In such processes, hydrogen embedded within a reactant alcohol mediates reductive coupling. By allowing alcohols to serve dually as ...
Cluster headache is a severely debilitating disorder that can remain unrelieved by current pharmacotherapy. Alongside ablative neurosurgical procedures, neuromodulatory treatments of deep brain stimulation (DBS) and occipital nerve simulation have emerged in the last few years as effective treatments for medically refractory cluster headaches. Pioneers in the field have sought to publish guidelines for neurosurgical treatment; however, only small case series with limited long-term follow-up have been published. Controversy remains over which surgical treatments are best and in which circumstances to intervene. Here we review current data on neurosurgical interventions for chronic cluster headache focusing upon DBS and occipital nerve stimulation, and discuss the indications for and putative mechanisms of DBS including translational insights from functional neuroimaging, diffusion weighted tractography, magnetoencephalography and invasive neurophysiology.
Over the past 7 years, deep brain stimulation (DBS) has been used in various centres to treat patients with intractable chronic cluster headache (CH). Results in these non-controlled studies were encouraging but need to be confirmed in controlled conditions. The aim of this study is to evaluate the efficacy and safety of DBS in chronic and treatment-resistant CH, in randomized placebo-controlled conditions.. Inclusion criteria are: patients with chronic CH (,3years), with daily attack and non response to adequate treatment (verapamil up 960 mg/d, lithium with plasmatic level 0.6-1 mEq/ ml, and association of both drugs). After induction of local anaesthesia, electrodes are implanted stereotactically in the postero-inferior hypothalamus according to the previously described coordinates, and connected to a sub-cutaneous generator. In this crossover, randomized, placebo-controlled double-blinded study, the efficacy of DBS is evaluated using comparison of two one-month sequences: one with ...
article{1234402, author = {Dhooghe, Matthias and Kenis, Sara and Vervisch, Karel and Lategan, Carmen and Smith, Peter and Chibale, Kelly and De Kimpe, Norbert}, issn = {0223-5234}, journal = {EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY}, keyword = {Aziridinium salts,Aziridines,Ring opening,Triaminopropanes,Antimalarial agents,INTERMEDIATE AZIRIDINIUM SALTS,PLASMODIUM-FALCIPARUM,PURINE DERIVATIVES,CHIRAL AZIRIDINES,1-ALKYL-2-(BROMOMETHYL)AZIRIDINES,CHEMOTHERAPY,EPOXIDES,POTENT,ASSAY,IONS}, language = {eng}, number = {2}, pages = {579--587}, title = {Synthesis of 2-(aminomethyl)aziridines and their microwave-assisted ring opening to 1,2,3-triaminopropanes as novel antimalarial pharmacophores}, url = {http://dx.doi.org/10.1016/j.ejmech.2010.11.037}, volume = {46}, year = {2011 ...
In the arena of enantioselective synthesis, titanium complexes wear the laurel wreath. Highly functionalized tetrathiafulvalenes: Riding along the synthetic trail from electrophilic alkynes
We report palladium(II)-functionalized MOF-253 (MOF-253-Pd(OAc) 2) as a recyclable catalyst to form all-carbon quaternary centers via conjugate additions of arylboronic acids to β,β-disubstituted enones in aqueous media. We demonstrate MOF-253-Pd(OAc) 2 can be reused 8 times to form ketone products in yields above 75% while maintaining its crystallinity. Additions of a range of stereoelectronically diverse arylboronic acids to a variety of β,β-disubstituted enones catalyzed by MOF-253-Pd(OAc) 2 occur in modest-to-high yields (34-95%). ...
Catalytic Hydroamination of Alkynes and Alkenes. Zhi-Yong,Han 14.Nov.,2009. Introduction Mechanistic Aspects Selected Reactions Involving Hydroamination. 1. Introduction. Problems:. slightly exothermic. but. a high reaction barrier. entropically negative. Amines: nucleophilic Slideshow 4750702 by idania
Au(I) catalysis has recently emerged as a powerful tool for the realization of a broad range of organic transformations. Despite this rapid development, attaining selectivity and maintaining catalyst stability remain significant challenges. Rational ligand design, such as the employment of NHC or TA ligands, has been used to confront these issues. This thesis focuses on the use of Au(I) catalysts bearing these ligands for the selective hydroalkynylation of enol ethers. By employing a TA-Au stabilized catalyst, [(OAr)3PAu(TA-H)]OTf, the intermolecular hydroalkynylation of enol ethers, a substrate that is well-known to promote decomposition of the gold cation, was efficiently achieved. As an expansion of this reaction, the NHC-Au catalyst, IPrAuNTf2, was utilized in a multicomponent system to promote the tandem hydroalkynylation of enol ethers formed in-situ via the cycloisomerization of alkynols. Further exploration of this tandem reaction revealed that IPrAuNTf2 catalyzes a cascade ring-expansion of the
very similar trifluoroacetic acid favors the formation of the (S)-isomer (entry 2). Evidently, the lactone is protonated by two different reaction mechanisms. Thus, this is a further example of a reversal of stereoselectivity on changing from a methyl to a trifluoromethyl group in a reaction partner. The results can be explained if it is assumed that owing to the nucleophilicity of the carbonyl oxygen atom, the acetic acid forms a dative bond with the boron atom. This adduct transfers the acidic proton to the enol in a cyclic transition state, for example 5, whereby the (R)-isomer is formed. A similar cyclic transition state was also postulated by Brown et al. for the protolysis of B-crotyl-9-borabicyclo[3.3.I]n0nane.[~I R In contrast, trifluoroacetic acid (TFA) protonates the enolate without prior binding at the boron atom. The reason for the reduced capability for coordination of TFA is the reduced nucleophilicity of the carbonyl oxygen atom due to the accepting ability of the ...
Close The Infona portal uses cookies, i.e. strings of text saved by a browser on the users device. The portal can access those files and use them to remember the users data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser. ...
Read "Highly functionalized cyclic β-amino acid moieties as promising scaffolds in peptide research and drug design, Amino Acids" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
A regioselective hydroboration of alkynes has been developed by using commercially available zinc triflate as a catalyst, in the presence of catalytic amount of NaBHEt3. The reaction tolerates a wide range of terminal alkynes having several synthetically useful functional groups and proceeds regioselectively to furnish hydroborated products in moderate to excellent yields. This system shows moderate chemoselectivity towards terminal C equivalent to C bond over terminal and internal C=C bond and internal C equivalent to C bond.. ...
A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimers type and dementia due to Parkinsons disease, is accomplished by the treatment of versatile, readily accessible (S)-(-)-2-methyl-2-propanesulfinamide with 3-hydroxyacetophenone. This protocol provides high yield and excellent enantiomeric excess in short step synthesis.
In a process which comprises catalytically hydrogenating the carbon-carbon double bonds of a conjugated diene polymer, the improvement which comprises using a catalyst composed of a porous powdery or granular carrier and supported thereon both Pd and at least one metal selected from the group consisting of the metals of Groups Ia, IIa, IIIa, IIIb, IVa, Va and VIa of the periodic table, Ge and Sb.
Mr. Klima authored an article titled "A highly ster and chemoselective synthesis of conjugated dienes by the palladium-catalyzed reaction of (E)-1-alkenylzirconium derivatives with alkenyl halides" in the 1978 edition of Tetrahedron Letters.. ...
A free platform for explaining your research in plain language, and managing how you communicate around it - so you can understand how best to increase its impact.
ethyl ester 5-{6-[2-(2,4-dichlorophenyl)ethylamino]-2-methoxypyridine-4-yl}-1-methyl-2,3-dihydro-1H-indole-2-carboxylic acid.. Suitable esters of compounds of the present invention containing a hydroxy group, are for example acetates, citrates, lactates, tartratami, malonate, oxalates, salicylates, propionate, succinate, fumarate, maleate, methylene-bis-b-hydroxynaphthoate, gentisate, isethionate, di-para-toluoyltartaric, methansulfonate, econsultancy, bansilalpet, para-toluensulfonate, cyclohexylsulfamate and hinata.. Suitable esters of compounds of the present invention containing a carboxyl group are, for example, esters, described in F.J. Leinweber, Drug Metab. Res., 1987, 18, page 379.. A particularly useful class of esters of compounds of the present invention containing a hydroxyl group may be formed from acid groups from those described by Bundgaard et al., J. Med. Chem., 1989, 32, page 2503-2507, and include substituted (aminomethyl)benzoate, for example, dialkylaminomethyl, in which ...
Ruthenium-Catalyzed Direct CH Amidation of Arenes Including Weakly Coordinating Aromatic Ketones. Kim, Jiyu; Kim, Jinwoo; Chang, Sukbokresearcher, CHEMISTRY-A EUROPEAN JOURNAL, v.19, no.23, pp.7328 - 7333, 2013- ...
A series of 5-aryl and 3,5-diaryl-2-amino-1,4-pyrazines and the derived imidazopyrazinones has been synthesized to study the chemical oxidative degradation of the bicyclic systems in vitro. Imidazopyrazinones mainly degraded following two independent
Cationic planar chiral (h6-arene)Mn(CO)3+ complexes : resolution, NMR study in chiral oriented solvents, applications to the enantioselective syntheses of 4-substituted cyclohexenones and of (h6-phosphinoarene)Mn(CO)3+ complexes ...
Video created by Eindhoven University of Technology for the course Improving your statistical inferences. 2000+ courses from schools like Stanford and Yale - no application required. Build career skills in data science, computer science, ...
A continuous process for manufacture of a polymer including branched and linear components comprising first polymerizing conjugated diene(s) in the presence of an organometallic initiator to a conversion that is at least 90% complete. A coupling agent is added to obtain a polymer including branched and linear components. The coupling agent is added at a ratio of about 0.3 to about 0.6 coupling equivalents to initiator equivalents.
See what Diene Sofitasari (dienesofitasari) has discovered on Pinterest, the worlds biggest collection of everybodys favorite things.
The 1,3-dipolar cycloaddition of trifluoromethylated propargylic alcohols 1 with azides in the presence of catalytic [Cp*RuCl2], afforded exclusively 4-trifluoroniethyl-1,4,5-trisubstituted-1,2,3-triazoles 2 in high yields. (c) 2008 Elsevier Ltd. All rights reserved ...
The iodine-catalyzed Prins cyclization of homoallylic alcohols and aldehydes was investigated under metal-free conditions and without additives. Anhydrous conditions and inert atmosphere are not required. The reaction of 2-(3,4-dihydronaphthalen-1-yl)propan-1-ol and 21 aldehydes (aliphatic and aromatic) in CH2Cl2 in the presence of 5 mol % of iodine gave 1,4,5,6-tetrahydro-2H-benzo[f]isochromenes in 54%-86% yield. Under similar conditions, the Prins cyclization of six alcohols containing an endocyclic double bond (primary, secondary, or tertiary) led to dihydropyrans in 52%-91% yield. The acyclic homoallylic alcohols gave 4-iodo-tetrahydropyran in 29%-41% yield in the presence of 50 mol % of iodine. This type of substrate is the main limitation of the methodology. The relative configuration of the products was assigned by NMR and X-ray analysis. The mechanism and the ratio of the products are discussed, based on DFT calculations.
Hydrogenation reactions are of great importance in scientific research and in industry productions. Herein, we designed a novel system to realize photocatalytic transfer hydrogenation by using solar light as the energy input and methanol as the hydrogen source. In this reaction, titania loaded with Pd-Pt bimetallic alloy nanocrystals as a cocatalyst exhibited photocatalytic performance that was remarkably superior to that exhibited by titania with Pd or Pt alone as the cocatalyst. This work has shed light on the rational design of multifunctional catalysts through selecting appropriate bimetallic alloys as efficient cocatalysts. Light up, as if you have a catalyst: Photocatalytic transfer hydrogenation is efficiently realized on Pd-Pt/TiO2 under mild reaction conditions with the use of light irradiation as the energy input and methanol as the hydrogen source at ambient temperature. The Pd-Pt alloy cocatalyst exhibits enhanced catalytic performance relative to that of the monometallic Pd or Pt ...
The preparation of chiral alcohols and amines by using iridium catalysis is reviewed. The methods presented include the reduction of ketones or imines by using hydrogen (hydrogenations), isopropanol, formic acid, or formate (transfer hydrogenations). Also dynamic and oxidative kinetic resolutions leading to chiral alcohols and amines are included. Selected literature reports from early contributions to December 2012 are discussed.. ...
The reaction mechanism for the palladium and amine cocatalyzed carbocyclization of aldehydes with alkynes has been investigated by means of density functional theory calculations and experiments. The Pd/amine cocatalyzed transformation is a carbocyclization of in situ generated enaminynes where the C-C bond-forming step is most likely promoted by a Pd(II) species. Notably, the latent Pd(0)/Pd(II) catalytic redox cycle of this metal/organo cooperative catalytic reaction can be merged with catalytic direct aerobic alcohol oxidation (Pd oxidase catalysis). (Chemical Equation Presented).. ...
Binding of rigid dendritic ruthenium complexes to carbon nanotubes. Homoallylic alcohol isomerization in water over an immobilized Ru(II) organometallic catalyst with mesoporous structure
Methodologies in Asymmetric Catalysis brings together leading scientists who have made major contributions to the field of asymmetric catalysis. This book assembles several new methodologies that are interdisciplinary by nature, incorporating organic synthesis, coordination chemistry, auto-catalysis, homogeneous and heterogeneous catalysis, kinetics and mechanism, etc. Thirteen chapters are included.
Landwehr, Anne. [Re(H)(NO)(L)(C5H4OH)] complexes and their application in hydrogenations and transfer hydrogenations. 2013, University of Zurich, Faculty of Science. ...
S)-3-Amino-2-(1-hydroxy-2,2-dimethylprop-1-yl)-quinazolin-4(3H)-one (Q*NH2) was prepared from (L)-tert-leucine and its 3-acetoxyamino derivative (Q*NHOAc) used to aziridinate a range of alkenes. In the presence of titanium (IV) tert-butoxide, Q*NHOAc was found to convert styrene, indene, butadiene and tert-butyl acrylate with complete diastereoselectivity into the corresponding N-Q* substituted aziridines in good yield; aziridination of methyl acrylate and -methylstyrene was also highly diastereoselective. In the absence of titanium (IV) tert-butoxide, aziridination proceeded with poor diastereoselectivity in every case.;The quinazolinone (Q*) ring has proved to be invaluable in directing or assisting the course of ring-opening of the N-(Q*) aziridines produced above. Thus Q* as a substituent on nitrogen was found to be sufficiently electron-withdrawing to activate the aziridine ring towards attack by nucleophiles in the absence of acid. The C-4 carbonyl oxygen of the quinazolinone (Q*) was ...
In a molecule, a stereocenter is a particular instance of a stereogenic element that is geometrically a point. A stereocenter or stereogenic center is any point in a molecule, though not necessarily an atom, bearing groups, such that an interchanging of any two groups leads to a stereoisomer. The term stereocenter was introduced in 1984 by Kurt Mislow and Jay Siegel. A chiral center is a stereocenter consisting of an atom holding a set of ligands (atoms or groups of atoms) in a spatial arrangement which is not superimposable on its mirror image. The concept of a chiral center generalizes the concept of an asymmetric carbon atom, i.e., a carbon atom bonded to four different entities, such that an interchanging of any two groups gives rise to an enantiomer. In organic chemistry, a chiral center usually refers to a carbon, phosphorus, or sulfur atom, though it is also possible for other atoms to be chiral centers, especially in areas of organometallic and inorganic chemistry. A molecule can have ...
Convenient transfer hydrogenation catalyzed by palladium-containing beads was performed using a SpinChem® rotating bed reactor (RBR). The set-up resulted in high product conversions throughout more than 10 consecutive batches without any need for filtration to recycle the catalyst.. ...
A series of enantiomerically pure ligands containing a combination of proline and DPEN groups have been prepared and employed in the asymmetric transfer hydrogenation of ketones. In the case of cyclic ketones, alcohols with ee values of up to 98 % were obtained.. ...
Organic compounds that contain nitrogen are very important intermediates in pharmaceutical and chemical industry. Hydroamination is the reaction that can form C-N bond with high atom economy. The research progress in metals catalyzed hydroamination of alkenes and alkynes from the perspective of reaction mechanism is categorized and summarized.
This thesis embraces three main sections: the development of new molecular scaffolds for the organocatalytic Diels-Alder reaction, extension of the studies upon the a-effect and ji-stacking interactions to acyl-ammonium catalysis and development of novel molecular structures for the aminocatalysed Baylis-Hillman reaction. Chapter 1 describes some of the recent advances made in metal-free asymmetric catalysis and sets the work involved within this thesis into context. Chapter 2 describes the investigation of the a-effect and the modulation of face-face ji-jt interactions as a platform for the development of a novel family of catalyst for the aminocatalysed Diels-Alder reaction. After initial investigation on the effect of different counter anions and alternative electron withdrawing groups within achiral catalysts, the a-effect and the face-face ji-jt interactions design concepts were combined within the structure of a series of arenes based on the 8-aryl menthamine scaffold. Experiments ...
Friedrich, E. C.; Niyati-Shirkhodaee, F. Regioselectivity and Solvent Effects in Cyclopropanation of Alkadienes. J. Org. Chem. ...
The A race produces alkadienes and alkatrienes (derivatives of fatty acids) wherein n is an odd number 23 through 31. The B ... see vegetable oil refining). Botryococcenes are preferred over alkadienes and alkatrienes for hydrocracking as botryococcenes ... The vast majority of these hydrocarbons are botryocuccus oils: botryococcenes, alkadienes and alkatrienes. Transesterification ...
Alkadienes are acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds. Alkadienes are also known as ...
The book also described 16 original methods of industrial synthesis and polymerization of dialkenes (alkadienes). In 1910s, ...
... alkadienes MeSH D02.455.326.271.665.146.240 --- butadienes MeSH D02.455.326.271.665.146.280 --- chloroprene MeSH D02.455. ...
The structure of a PAH influences whether and how the individual compound is carcinogenic.[51][55] Some carcinogenic PAHs are genotoxic and induce mutations that initiate cancer; others are not genotoxic and instead affect cancer promotion or progression.[55][56] PAHs that affect cancer initiation are typically first chemically modified by enzymes into metabolites that react with DNA, leading to mutations. When the DNA sequence is altered in genes that regulate cell replication, cancer can result. Mutagenic PAHs, such as benzo[a]pyrene, usually have four or more aromatic rings as well as a "bay region", a structural pocket that increases reactivity of the molecule to the metabolizing enzymes.[57] Mutagenic metabolites of PAHs include diol epoxides, quinones, and radical PAH cations.[57][58][59] These metabolites can bind to DNA at specific sites, forming bulky complexes called DNA adducts that can be stable or unstable.[53][60] Stable adducts may lead to DNA replication errors, while unstable ...
In systematic chemical nomenclature, alkynes are named with the Greek prefix system without any additional letters. Examples include ethyne or octyne. In parent chains with four or more carbons, it is necessary to say where the triple bond is located. For octyne, one can either write 3-octyne or oct-3-yne when the bond starts at the third carbon. The lowest number possible is given to the triple bond. When no superior functional groups are present, the parent chain must include the triple bond even if it is not the longest possible carbon chain in the molecule. Ethyne is commonly called by its trivial name acetylene.. In chemistry, the suffix -yne is used to denote the presence of a triple bond. In organic chemistry, the suffix often follows IUPAC nomenclature. However, inorganic compounds featuring unsaturation in the form of triple bonds may be denoted by substitutive nomenclature with the same methods used with alkynes (i.e. the name of the corresponding saturated compound is modified by ...
The topic under discussion here is Alkadienes, allylic systems, and pigments - The WikiPremed MCAT Course ...
0 onjugated Systems hapter 0 onjugation in Alkadienes and Allylic Systems onjugated systems are those in which a π-bond is ... Conjugation in Alkadienes and Allylic Systems. Class Notes. B. The allyl group is both a common name and an accepted IUPAC name ... 1 . 0 onjugated Systems hapter 0 onjugation in Alkadienes and Allylic Systems onjugated systems are those in which a π-bond is ... Chapter 10 Conjugation in Alkadienes and Allylic Systems Chapter 10 suggested problems: I. The allyl group Class Notes A. B. ...
Conjugation in Alkadienes & Allylic Systems What are the differences between vinylic & allylic hydrogens in a Cyclohexene (ie. ...
B. braunii: alkadienes;. C. vulgaris: carotenoids (canthaxanthin, astaxanthin);. D. salina: β-carotene (trans- and cis-isomer ...
Hydrogenation of Alkadienes and Poly-Enes Pages 357-394 * Hydrogenation of Alkynes ...
Alkadienes / chemistry. Alkynes / chemical synthesis, chemistry*. Boronic Acids / chemistry*. Bromine Compounds / chemistry. ... 0/Aldehydes; 0/Alkadienes; 0/Alkynes; 0/Boronic Acids; 0/Bromine Compounds; 0/Propanols; 4AV0LZ8QKB/propadiene; E920VF499L/ ...
Chapter 10: Conjugation in Alkadienes and Allylic Systems 10.kas. 11. 01 02 03 04 05 06 07 08 09 10 11 ...
Chapter 10: Conjugation in Alkadienes and Allylic Systems 10.P. 19. 001 002 003 004 005 006 007 008 009 010 011 012 012.alt 013 ...
Conjugation in Alkadienes and Allylic Systems. *Classes, stability, bonding and resonance energy of dienes ...
... on Shapeways. Learn more before you buy, or discover other cool products in Sculptures.
... cis-carboxylic alkadienes, cis-carboxylic alkatrienes, and poly-maleic anhydrides. Other cleavable linkers are linkers capable ...
Soják, L.; Královicová, E.; Ostrovský, I.; Leclercq, P.A., Retention behaviour of conjegated and isolated n-alkadienes. ...
Soják, L.; Královicová, E.; Ostrovský, I.; Leclercq, P.A., Retention behaviour of conjegated and isolated n-alkadienes. ...
Homologs of Ethylbenzene from Adducts of Alkadienes with Methylethylmaleic Anhydride, Zh. Obshch. Khim., 1957, 27, 1784. [all ...
An n-alkatriene and some n-alkadienes from the A race of the green alga Botryococcus braunii. Phytochemistry, 25, 1869.CrossRef ...
2000) or deterrent substances, which prevent attack (e.g., possible alkadienes secreted through the cuticule of Formicoxenus ...
Friedrich, E. C.; Niyati-Shirkhodaee, F. Regioselectivity and Solvent Effects in Cyclopropanation of Alkadienes. J. Org. Chem. ...
11 Conjugation in Alkadienes and Allylic Systems 12 Arenes and Aromaticity 13 Electrophilic and Nucleophilic Aromatic ... 11 Conjugation in Alkadienes and Allylic Systems 12 Arenes and Aromaticity 13 Electrophilic and Nucleophilic Aromatic ...
Block copolymers of alkadienes and monovinyl arenes US4174360A (en) * 1977-08-02. 1979-11-13. Phillips Petroleum Company. ... Block copolymers of alkadienes and monovinyl arenes US4049753A (en) * 1976-04-19. 1977-09-20. Phillips Petroleum Company. ...
Publications] H.Ishii, et al.: Stereoselective Tandem Cyclization of l, l-Diphenyl-l, n-alkadienes via Photoinduced Electron ... Publications] H.Ishii, et al.: Stereoselective Tandem Cyclization of 1, 1-Diphenyl-1, n-alkadienes via Photoinduced Electron ... Publications] H.Ishii,et al.: Stereoselective Tandem Cyclization of 1,1-Diphenyl-1,n-alkadienes via Photoinduced Electron ...
The A race produces alkadienes and alkatrienes (derivatives of fatty acids) wherein n is an odd number 23 through 31. The B ... see vegetable oil refining). Botryococcenes are preferred over alkadienes and alkatrienes for hydrocracking as botryococcenes ... The vast majority of these hydrocarbons are botryocuccus oils: botryococcenes, alkadienes and alkatrienes. Transesterification ...
Alkadienes are acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds. Alkadienes are also known as ...
High purity alkadienes by extractive distillation US5006206A (en) 1991-04-09. Propylene oxide purification ...
Studies of 1,1,4,4-Tetrafluoro- 1,3-alkadienes. Journal of the American Chemical Society, 87 (6). pp. 1339-1344. ISSN 0002-7863 ...
The book also described 16 original methods of industrial synthesis and polymerization of dialkenes (alkadienes). In 1910s, ...
  • A convenient one-pot synthesis of 1,3-cyclo-alkadienes via a regioselective dehydrogenation of the corresponding cycloalkenes has been developed recently by the group of Professor Yoshiharu Iwabuchi from Tohoku University (Japan). (thieme.de)
  • 1 . 0 onjugated Systems hapter 0 onjugation in Alkadienes and Allylic Systems onjugated systems are those in which a π-bond is connected or conjugated (from the Latin conjugare which means to link r yoke together) to another system that contains either a p-orbital or another π-bond. (docplayer.net)
  • En.wikipedia.org The boiling points of the pentane isomers range from about 9 to 36 °C. As is the case for other alkanes, the more thickly branched isomers tend to have lower boiling points. (lawandicome.co)
  • This strategy is not limited to the oxidation of diols, but can be extended to the site‐selective reaction of many similar multifunctional linear molecules, such as the reduction of alkadienes. (ntu.edu.sg)