Alkene An unsaturated hydrocarbon

Alkene an unsaturated hydrocarbon containing a carbon-carbon double bond. The general formula is C H2 . (22.2) Alkyne an unsaturated hydrocarbon containing a triple carbon-carbon bond. The general formula is C H2 2. (22.2) Alloy a substance that contains a mixture of elements and has metallic properties. (16.4)... 

Alkene an unsaturated hydrocarbon containing a carbon-carbon double bond. The general formula is C H2 . 

Alkene, A general term for an unsaturated hydrocarbon, CnH2n an olefin,... 

The Heck reaction is a C-C coupling reaction where an unsaturated hydrocarbon or arene halide/triflate/sulfonate reacts with an alkene in presence of a base and Pd(0) catalyst so as to form a substituted alkene. Kaufmann et al. showed that the Heck reaction carried out in presence of ILs such as tetra-alkyl ammonium and phosphonium salts without the phosphine ligands, resulted in high yields of product. They attributed the activity to the stabilizing effect of ammonium and phosphonium salts on Pd(0) species. Carmichael et al. used ionic liquids containing either A,A -dialkylimidazolium and A-alkylpyridinium cations with anions such as halide, hexafluorophosphate or tetrafiuoroborate to carry out reactions of aryl halide and benzoic anhydride with ethyl and butyl acrylates in presence of Pd catalyst. An example of iodobenzene reacting with ethyl acrylate to give trans-et vy cinnamate is shown in Scheme 14. 

O aikene an unsaturated hydrocarbon that contains at least one double bond between two of the carbon atoms in the chain the simplest aikene is ethene, CjH4 O homologous series a family of organic compounds with similar chemical properties as they contain the same functional group alkenes, alcohols, for instance O isomers molecules with the same molecular formula but different stnictural formulae O substitution reaction a reaction in which one or more hydrogen atoms in a hydrocarbon are replaced by atoms of another element... 

Nickel-catalyzed cyclizations, couplings, and cycloadditions involving three reactive components have been an active area of research for the past decade [39,40]. Central to these reactions is the involvement of a low-valent nickel capable of facilitating oxidative coupling of an unsaturated hydrocarbon (such as an alkyne, allene, or alkene) and a carbonyl substrate (such as an aldehyde or ketone). The use of NHCs as ligands has been evaluated for couplings of aldehydes. Such reactions typically afford O-protected allylic alcohols in good yields. 

The ability of a p-carbene to react with an unsaturated hydrocarbon and form an enlarged dimetallocycle encourages speculation over their role in such processes as alkene metathesis and Fischer-Tropsch synthesis. In Scheme 6 a possible mechanism for metathesis initiated by a p-carbene is presented, owing much to other workers (T7,22). Reactions of p-carbenes with alkenes are under investigation in our laboratory. Recently Pettit has observed that the p-methylene complex [Fe2(C0)8(p-CH2)] generates propene when subjected to a pressure of ethene and has also suggested the intermediacy of a three-carbon dimetallocycle (23). 

Addition of Br2 to alkenes is a useful reaction which shows us if a hydrocarbon is saturated or unsaturated. When an unknown hydrocarbon is added to a solution of Br2 in water, if the color of solution disappears, it is an unsaturated hydrocarbon (alkene or all e). If color doesn t change, it is an alkane. 

The rules for naming an unsaturated hydrocarbon with fewer than four carbon atoms are similar to those for naming alkanes. A two-carbon alkene is named ethene, with the suffix -ene indicating that the molecule is an alkene. A three-carbon alkyne is named propyne, with the suffix -yne indicating that the molecule is an alkyne. 

The other approach to 2-thioxo-l,2-thiaphospholanes 108 and 110 is based on the direct reaction of an unsaturated hydrocarbon, phosphorus pentasulfide and a thiophosphoric acid halide under drastic conditions (autoclave, 150-200 °C, 10-18 h) [142, 143], When cyclic alkenes (e.g. cyclohexene) are used as the starting substrates, bicyclic compounds are formed with one of the rings representing 1,2-thiaphos-pholane (Scheme 64). These reaction products are used as antioxidant additives for motor oils, polymers and agrochemicals. 

Two procedures are available for the dichlorophosphonation of alkenes and alkynes. The first of these, namely the use of PCI3 and oxygen, has already been mentioned briefly in connection with reactions which involved phenylethene. The second procedure involves the interaction of an unsaturated hydrocarbon with PCI5 and this, too, has been discussed to some extent in connection with those reactions which particularly involve arylethenes (Chapter 2, Sections III.A and VI.D). 

An unsaturated hydrocarbon containing a carbon-carbon triple bond alkenes have the general formula C H2 2-... 

Alkenes are unsaturated hydrocarbons that contain a carbondouble bond, i.e., two adjacent carbon atoms are joined by two bonds. Alkenes have the general formula C H2 , where n is an integer greater than 1. The simplest member of the alkene family is C2H4 (lUPAC name ethene common name ethylene)... 

Indicate whether each statement is true or false, (a) Alkanes do not contain any carbon-carbon multiple bonds, (b) Cyclobutane contains a four-membered ring, (c) Alkenes contain carbon-carbon triple bonds, (d) Alkynes contain carbon-carbon double bonds, (e) Pentane is a saturated hydrocarbon but 1-pentene is an unsaturated hydrocarbon, (f) Cyclohexane is an aromatic hydrocarbon, (g) The methyl group contains one less hydrogen atom than methane. 

Alkene al- ken [ISV alkyl+ene] (1899) n. An unsaturated hydrocarbon with the general formula C H2 . Contains a C=C double bond. Same as olefin. Morrison RT, Boyd RN (1992) Organic Chemistry, 6th edn. Prentice-Hall, Englewood Cliffs, NJ. 

A hydrocarbon that contains one or more carbon-carbon double bonds, triple bonds, or benzene rings is classified as an unsaturated hydrocarbon. We study alkanes (saturated hydrocarbons) in this chapter. We study alkenes and alkynes (both unsaturated hydrocarbons) in Chapters 4 and 5, and arenes (also unsaturated hydrocarbons) in Chapters. 

IN THIS CHAPTER, we begin our study of unsaturated hydrocarbons. An unsaturated hydrocarbon is a hydrocarbon that has fewer hydrogens bonded to carbon than an alkane has. There are three classes of unsaturated hydrocarbons alkenes, alkynes, and arenas. Alkenes contain one or more carbon-carbon double bonds, and alkynes contain one or more carbon-carbon triple bonds. Ethene (ethylene) is the simplest alkene, and ethyne (acetylene) is the simplest alkyne ... 

An unsaturated hydrocarbon contains one or more carbon-carbon double or triple bonds. The term unsaturation indicates that fewer hydrogens are bonded to carbon than in an alkane, C 2n+i- three most important classes of unsaturated hydrocarbons are alkenes, alkynes, and arenes. Alkenes contain a carbon-carbon double bond and, with one double bond and no rings, have the general formula C 2n- Alkynes contain a carbon-carbon triple bond and, with one triple bond and no rings, have the general formula CJi2 2- The simplest alkene is ethylene, and the simplest alkyne is acetylene. 

The alkenes are also hydrocarbons, and therefore contain carbon and hydrc en only. They have the general formula C H2 . The alkenes are unsaturated hydrocarbons containing a carbon-carbon double bond this double bond is made up of a sigma (a) bond and a pi (jt) bond. The carbon atoms which form the double bond have an arrangement of groups around them which is trigonal planar with angles of 120°, as shown for H /H... 

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