title: Borane-Catalyzed Reductive α-Silylation of Conjugated Esters and Amides Leaving Carbonyl Groups Intact.
abstract: Described herein is the development of the B(C6F5)3-catalyzed hydrosilylation of α,β-unsaturated esters and amides to afford synthetically valuable α-silyl carbonyl products. The α-silylation occurs chemoselectively, thus leaving the labile carbonyl groups intact. The reaction features a broad scope of both acyclic and cyclic substrates, and the synthetic utility of the obtained α-silyl carbonyl products is also demonstrated. Mechanistic studies revealed two operative steps: fast 1,4-hydrosilylation of conjugated carbonyls and then slow silyl group migration of a silyl ether intermediate.
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 305-701 (Korea).|Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Deajeon 305-701 (Korea).
authors.forename: Youngchan
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Deajeon 305-701 (Korea). sbchang@kaist.ac.kr.|Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Deajeon 305-701 (Korea). sbchang@kaist.ac.kr.
authors.forename: Sukbok
authors.initials: S
authors.lastname: Chang
keywords: boron; chemoselectivity; conjugation; hydrosilylation; reaction mechanisms