Vinyltriarylbismuthonium Salts: Powerful Vehicles for α-Vinylation of Carbonyl Compounds

Abstract

α-Vinyl-carbonyl compounds are a class of orthogonally functionalized molecules, wherein the intrinsic C�O and C�C bonds can be used to unlock distinctly different reactivities. In this report, we present a simple method for the direct αvinylation of carbonyl compounds utilizing vinyltriarylbismuthonium ("Vinyl-Bis") salts, which are stable and readily preparable on a decagram scale. This transformation is accomplished efficiently through the reaction of an in situ generated Li-enolate intermediate with a Vinyl-Bis reagent, leading to the formation of α-vinylated carbonyl compounds in good to excellent yields and with a remarkably broad substrate scope. Critically, this vinylation method is effective for enolates generated via numerous methods, enabling the sequencing of reactions that generate enolates with the vinylation step and the ready synthesis of diversely functionalized compounds, thereby underscoring the versatility and practicality of this method. Analogous reactions of discrete Lienolates with other vinyl units and with aryl groups are also demonstrated.