title: Synthesis of α-silylmethyl-α,β-unsaturated imines by the rhodium-catalyzed silylimination of primary-alkyl-substituted terminal alkynes.
abstract: In contrast to our previous report on the rhodium-catalyzed reaction of terminal alkynes with equimolar amounts of hydrosilanes and isocyanides leading to (E)- or (Z)-β-silyl-α,β-unsaturated imines A, the addition of an excess molar amount of hydrosilanes relative to isocyanides in the reaction of primary-alkyl-substituted terminal alkynes results in the production of α-silylmethyl-α,β-unsaturated imines B. Various isocyanides bearing tert-butyl and 1-adamantyl groups gave B with good product selectivity. Z isomers were formed stereoselectively in many cases. Regarding the mechanism for this reaction, when the hydrosilane was added to the reaction mixture in two portions, unsaturated imines A were initially formed, which then underwent double-bond isomerization, probably catalyzed by a Rh-H species, to give B.
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Osaka University , Suita, Osaka 565-0871, Japan.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Fukumoto
authors.forename: Hiroto
authors.initials: H
authors.lastname: Shimizu
authors.forename: Aya
authors.initials: A
authors.lastname: Tashiro
authors.forename: Naoto
authors.initials: N
authors.lastname: Chatani