title: Transition-metal-free coupling reaction of vinylcyclopropanes with aldehydes catalyzed by tin hydride.
abstract: Donor-acceptor cyclopropanes are useful building blocks for catalytic cycloaddition reactions with a range of electrophiles to give various cyclic products. In contrast, relatively few methods are available for the synthesis of homoallylic alcohols through coupling of vinylcyclopropanes (VCPs) with aldehydes, even with transition-metal catalysts. Here, we report that the hydrostannation of vinylcyclopropanes (VCPs) was effectively promoted by dibutyliodotin hydride (Bu2 SnIH). The resultant allylic tin compounds reacted easily with aldehydes. Furthermore, the use of Bu2 SnIH was effectively catalytic in the presence of hydrosilane as a hydride source, which established a coupling reaction of VCPs with aldehydes for the synthesis of homoallylic alcohols without the use of transition-metal catalysts. In contrast to conventional catalytic reactions of VCPs, the presented method allowed the use of several VCPs in addition to conventional donor-acceptor cyclopropanes.
authors.affiliation: Research Center for Environmental Preservation, Osaka University, 2-4 Yamadaoka, Suita, Osaka 565-0871 (Japan).
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Ieki
authors.forename: Yuria
authors.initials: Y
authors.lastname: Kani
authors.forename: Shinji
authors.initials: S
authors.lastname: Tsunoi
authors.forename: Ikuya
authors.initials: I
authors.lastname: Shibata
keywords: allylation; hydrides; hydrostannation; small-ring systems; tin