title: Nickel-catalyzed regioselective synthesis of tetrasubstituted alkene using alkylative carboxylation of disubstituted alkyne.
abstract: [Reaction: see text] Syntheses of alpha-silyl-beta,beta'-dialkyl alpha,beta-unsaturated carboxylic acids were achieved from silylated alkyne, carbon dioxide, and a zinc reagent using a catalytic amount of nickel complex in the presence of an excess amount of DBU. The regioselectivity of the introduction of CO2 into disubstituted alkyne is dependent on the electronic property of the substituent R on the alkyne because the thermodynamic stability of oxanickelacycle IV or V should be affected by conjugation of the substituent R with the carboxyl group in IV or V.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Shimizu
authors.forename: Masanori
authors.initials: M
authors.lastname: Takimoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
authors.forename: Miwako
authors.initials: M
authors.lastname: Mori
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D000478:Alkylation; D000480:Alkynes / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D000480:Alkynes; D002245:Carbon Dioxide; D009532:Nickel