Alkynic synthesis

A second strategy for alkyne synthesis involving functional group transformation reactions is described m the following section... 

An alkyne is a hydrocarbon that contains a carbon-carbon triple bond. Alkyne carbon atoms are sp-hybridized, and the triple bond consists of one sp-sp a bond and two p-p tt bonds. There are relatively few general methods of alkyne synthesis. Two good ones are the alkylation of an acetylide anion with a primary-alkyl halide and the twofold elimination of HX from a vicinal dihalide. 

It must also be pointed out that the alkyne synthesis through the FVP process can also be extended to bis()5-oxo phosphonium ylides) for the preparation of 1.3-diynes compounds [16]. 

Chiral active pharmaceutical ingredients, 18 725-726. See also Enantio- entries Chiral additives, 6 75—79 Chiral alcohols, synthesis of, 13 667-668 P-Chiral alcohols, synthesis of, 13 669 Chiral alkanes, synthesis of, 13 668-669 Chiral alkenes, synthesis of, 13 668—669 Chiral alkoxides, 26 929 Chiral alkynes, synthesis of, 13 668-669 Chiral ammonium ions, enantiomer recognition properties for, 16 790 Chiral ansa-metallocenes, 16 90 Chiral auxiliaries, in oxazolidinone formation, 17 738—739... 

Hull MW, Sevov SC (2007) Addition of alkenes to deltahedral zintl clusters by reaction with alkynes synthesis and stmcture of [Fc-CH=CH-Ge9CH-Fc] an organo-zinti-organometal-lic anion. Angew Chem Int Ed 46 6695-6698... 

Multimetallic complexes, molybdenocene dihydrides, 5, 570 Multimetallic nickel-alkynes, synthesis and reactivity, 8, 145 Multinuclear chromium(II) complexes, with halides, alkyls,... 

Interaction of Metal Atoms and Alkynes Synthesis of Cu-Acetylene Complexes [548]... 

The simplest route to aldehydes and ketones using the same strategy is oxidation of an alcohol. So the analysis involves FGI back to the alcohol and then a C-C disconnection of one of the bonds next to the OH group. Lythgoe4 wanted to make a series of ketones 34 with various R groups to demonstrate a new alkyne synthesis. Disconnection of the C-R bond of the alcohol 35 meant that they could all be made from aldehyde 36 which can be made by the same strategy. 

Maudru, E. et al. Radical Cyclisation of Carbohydrate Alkynes Synthesis of Highly Functionalised Cyclohexanes and Carbasugars. 3.1 1998 [150]... 

We reported that the palladium-catalyzed three-component coupling reaction of the activated alkynes 41, allyl methyl carbonate 5b, and trimethylsilyl azide 42 gave the 2-allyl-1,2,3-triazoles 43. The reaction proceeds via the [3 + 2] cycloaddition of tt-allylpalladium azide 44 to the alkynes 41, followed by the formation of (-allyl)(r]5-triazoyl)-palladium 45 (Scheme 16) [51]. However, this method was limited only for activated alkynes. Synthesis of the triazoles 47 from the nonactivated terminal alkynes 46 was achieved by the three-... 

Blitzke T, Sicker D, Wilde H (1995) Diethyl 2-oxopent-3-ynedioate synthesis and first cyclizations of a novel, reactive alkyne. Synthesis 236-238... 

K. Sonogashira, Sonogashira Alkyne Synthesis, in Handbook of Organopalladium Chemistry for Organic Synthesis , ed. E. Negishi, John Wiley Sons, Hohoken, NJ, 2002, p. 493. 

Various cyclopropenone derivatives react with peracids to yield the corresponding alkynes as primary products. However, the alkynes are themselves oxidized under the reaction conditions and the reaction is impractical as an alkyne synthesis. Two possible modes of alkyne formation are depicted in equation 97" ". Reaction of diphenylcyclopropenone with singlet oxygen or potassium permanganate gives" " desoxybenzoin. 

Maudru, E, Singh, G, Wightman, R H, Radical cyclisation of carbohydrate alkynes synthesis of highly functionalised cyclohexanes and carbasugars, Chem. Commun., 1505-1506, 1998. 

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