Phosphine-catalyzed asymmetric [4+1] annulation of activated α,β-unsaturated ketones with Morita–Baylis–Hillman carbonates: enantioselective synthesis of spirooxindoles containing two adjacent quaternary stereocenters

Abstract

The asymmetric [4+1] annulation of activated α,β-unsaturated ketones with MBH carbonates catalyzed by bifunctional thiourea–phosphine catalysts derived from an axially chiral binaphthyl scaffold has been developed, giving spirooxindoles with two adjacent quaternary stereocenters in good yields with high enantioselectivities and moderate diastereoselectivities under mild conditions.