Phosphine-catalyzed asymmetric aza-Morita–Baylis–Hillman reaction of endocyclic ketimines and activated alkenes

Abstract

A novel phosphine-catalyzed asymmetric aza-Morita–Baylis–Hillman reaction of endocyclic ketimines with vinyl ketone or acrolein has been presented. This approach resulted in densely functionalized adducts with moderate to high yields and enantioselectivities (up to 97% yield, up to 97% ee), with the feature of a C2 tetra-substituted chiral center on a 3-oxindole scaffold. A wide variety of substrates were compatible with this methodology, and diverse enantiomeric products could be obtained through a catalyst switching strategy. A series of transformations further demonstrated the utility of this methodology.