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Ethenolysis
In organic chemistry, ethenolysis is a chemical process in which internal olefins are degraded using ethylene () as the reagent. The reaction is an example of cross metathesis. The utility of the reaction is driven by the low cost of ethylene as a reagent and its selectivity. It produces compounds with terminal alkene functional groups (α-olefins), which are more amenable to other reactions such as polymerization and hydroformylation. The general reaction equation is: :\ce + \longrightarrow \ce + \ce Ethenolysis is a form of methylenation, i.e., the installation of methylene () groups. Applications Using ethenolysis, higher molecular weight internal alkenes can be converted to more valuable terminal alkenes. The Shell higher olefin process (SHOP process) uses ethenolysis on an industrial scale. The SHOP α-olefin mixtures are separated by distillation, the higher molecular weight fractions are isomerized by alkaline alumina catalysts in the liquid phase. The resulting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olefin Metathesis
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. Catalysts The reaction requires metal catalysts. Most commercially important processes employ heterogeneous catalysts. The heterogeneous catalysts are often prepared by in-situ activation of a metal halides (MClx) using organoaluminium or organotin compounds, e.g. combining MClx–EtAlCl2. A typical catalyst support is alumina. Commercial catalysts are often based on molybdenum and ruthenium. Well-defined organometallic co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-decene
Decene is an organic compound with the chemical formula . Decene contains a chain of ten carbon atoms with one double bond, making it an alkene. There are many isomers of decene depending on the position and geometry of the double bond. Dec-1-ene is the only isomer of industrial importance. As an alpha olefin, it is used as a comonomer in copolymers and is an intermediate in the production of epoxides, amines, oxo alcohols, synthetic lubricants, synthetic fatty acids and alkylated aromatics. The industrial processes used in the production of dec-1-ene are oligomerization of ethylene by the Ziegler process or by the cracking of petrochemical waxes. In ethenolysis, methyl oleate, the ''methyl ester'' of oleic acid, converts to 1-decene and methyl 9- decenoate: ::\overset + \longrightarrow \overset + \overset Dec-1-ene has been isolated from the leaves and rhizome of the plant '' Farfugium japonicum'' and has been detected as the initial product in the microbial degradation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oleic Acid
Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega-9 fatty acid, abbreviated with a lipid number of 18:1 ''cis''-9, and a main product of Δ9 desaturase. It has the formula CH3(CH2)7CH=CH(CH2)7COOH. The name derives from the Latin word ''oleum'', which means oil. It is the most common fatty acid in nature. The salts and esters of oleic acid are called oleates. Occurrence Fatty acids (or their salts) often do not occur as such in biological systems. Instead fatty acids such as oleic acid occur as their esters, commonly triglycerides, which are the greasy materials in many natural oils. Oleic acid is the most common monounsaturated fatty acid in nature. It is found in fats (triglycerides), the phospholipids that make membranes, cholesterol esters, and wax esters. Triglycerides of oleic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylenation
In organic chemistry, methylenation is a chemical reaction that inserts a methylene () group into a chemical compound: :\ce + \longrightarrow \ce\ce Typically, the reaction is used to prepare terminal alkenes from aldehydes and, less frequently, ketones. Methods Methylene-for-oxo reactions A common method for methylenation involves the Wittig reaction using methylenetriphenylphosphorane with an aldehyde (Ph = phenyl, ): :RCHO + Ph3P=CH2 -> RCH=CH2 + Ph3PO A related reaction can be accomplished with Tebbe's reagent, which is sufficiently versatile to allow methylenation of esters: :RCO2R' + Cp2Ti(Cl)CH2AlMe2 -> RC(OR')=CH2 + Cp2TiOAlMe2Cl Other less well-defined titanium reagents, e.g., Lombardo's reagent, effect similar transformations. : Carbanions derived from methylsulfones have also been employed, equivalently to the Wittig reaction. Other approaches Ethenolysis is a method for methylenation of internal alkene as illustrated by the following example: :\ce + \longrighta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes physical and chemical properties, and evaluation of chemical reactivity to understand their behavior. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical ( in silico) study. The range of chemicals studied in organic chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but also containing other elements, especially oxygen, nitrogen, sulfur, phosphorus (included in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decenoic Acid
Decenoic acid is any mono-carboxylic acid with an unbranched chain of ten carbons connected by eight single bonds and one double bond; that is, a chemical compound with formula ––––H, where ''k'' is between 0 and 7 inclusive. There are fifteen of these compounds, that can be identified by the position ''k''+2 of the double bond and (for ''k'' ≤ 6) the configuration (''cis'' or ''trans'') of the single bonds adjacent to it. Decenoic acids are technically mono-unsaturated fatty acids (with code C10:1), although they are relatively rare in nature. Examples Free acids and esters Some isomers (and esters thereof) that have received attention are * ''cis''-2-decenoic acid or (2''Z'')-dec-2-enoic acid. (CAS 15790-91-7, Nikkaji J1.577.978K) Produced by ''Pseudomonas aeruginosa'', inhibits biofilm formation. * ''trans''-2-decenoic acid or (2''E'')-dec-2-enoic acid. Flavoring agent (CAS 334-49-6, Nikkaji J98.042K, FEMA 3913, JECFA 1372, FDA 332T8TH7B1); Density: 0.92-0.93 25&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclooctene
Cyclooctene is the cycloalkene with a formula . Its molecule has a ring of 8 carbon atoms, connected by seven single bonds and one double bond. Cyclooctene is notable because it is the smallest cycloalkene that can exist stably as either the ''cis'' or ''trans'' stereoisomer, with ''cis''-cyclooctene being the most common. Theoretical analysis implies a total of 16 conformational and configurational isomers, all chiral, forming 8 enantiomeric In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical ant ... pairs. The ''cis'' isomer can adopt various conformations, the most stable one being shaped like a ribbon. The most stable conformation of ''trans''-cyclooctene is shaped like the 8-carbon equivalent of the chair conformation of cyclohexane. Longer cycloalkene rings such as the ten-c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhenium(VII) Oxide
Rhenium(VII) oxide is the inorganic compound with the formula Re2 O7. This yellowish solid is the anhydride of HOReO3. Perrhenic acid, Re2O7·2H2O, is closely related to Re2O7. Re2O7 is the raw material for all rhenium compounds, being the volatile fraction obtained upon roasting the host ore. Structure Solid Re2O7 consists of alternating octahedral and tetrahedral Re centres. Upon heating, the polymer cracks to give molecular (nonpolymeric) Re2O7. This molecular species closely resembles manganese heptoxide, consisting of a pair of ReO4 tetrahedra that share a vertex, i.e., O3Re–O–ReO3. Synthesis and reactions Rhenium(VII) oxide is formed when metallic rhenium or its oxides or sulfides are oxidized at in air. Re2O7 dissolves in water to give perrhenic acid. Heating Re2O7 gives rhenium dioxide, a reaction signalled by the appearance of the dark blue coloration:O. Glemser "Rhenium" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,5-Cyclooctadiene
Cycloocta-1,5-diene is a cyclic hydrocarbon with the chemical formula , specifically . There are three configurational isomers with this structure, that differ by the arrangement of the four C–C single bonds adjacent to the double bonds. Each pair of single bonds can be on the same side () or on opposite sides () of the double bond's plane; the three possibilities are denoted , , and ; or (), (), and (). (Because of overall symmetry, is the same configuration as .) Generally abbreviated COD, the isomer of this diene is a useful precursor to other organic compounds and serves as a ligand in organometallic chemistry. It is a colorless liquid with a strong odor. 1,5-Cyclooctadiene can be prepared by dimerization of butadiene in the presence of a nickel catalyst, a coproduct being vinylcyclohexene. Approximately 10,000 tons were produced in 2005. Organic reactions COD reacts with borane to give 9-borabicyclo .3.1onane, commonly known as 9-BBN, a reagent in organic chemistr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,5-Hexadiene
1,5-Hexadiene is the organic compound with the formula (CH)(CH=CH). It is a colorless, volatile liquid. It is used as a crosslinking agent and precursor to a variety of other compounds. Synthesis 1,5-Hexadiene is produced commercially by the ethenolysis of 1,5-cyclooctadiene: :(CHCH=CHCH) + 2 CH=CH → 2 (CH)CH=CH The catalyst is derived from ReO on alumina. A laboratory-scale preparation involves reductive coupling of allyl chloride Allyl chloride is the organic compound with the formula C H2=CHCH2 Cl. This colorless liquid is insoluble in water but soluble in common organic solvents. It is mainly converted to epichlorohydrin, used in the production of plastics. It is a ch ... using magnesium: :2 ClCHCH=CH + Mg → (CH)(CH=CH) + MgCl References Alkadienes Monomers {{Hydrocarbons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
