Highly enantioselective direct allylic alkylation of butenolides with Morita–Baylis–Hillman carbonates catalyzed by chiral squaramide-phosphine

Abstract

Asymmetric vinylogous allylic alkylation of β,γ-butenolides with Morita–Baylis–Hillman carbonates has been developed to construct γ,γ-disubstituted butenolides containing adjacent quaternary and tertiary chiral centers.