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.

The title reaction is promoted by a bifunctional thiourea-phosphine catalyst derived from an axially chiral binaphthyl scaffold affording spirooxindoles (III) with high enantioselectivities but only moderate diastereoselectivities. [ABSTRACT FROM AUTHOR]