Organocatalytic direct asymmetric vinylogous Mannich reaction of γ-butenolides with isatin-derived ketimines

The first direct asymmetric vinylogous Mannich reaction of gamma-butenolides with isatin-derived ketimines has been effectively realized promoted by a bifunctional quinidine-derived catalyst. A series of chiral 3-aminooxindole derivatives bearing adjacent tertiary and quaternary stereocenters with the butenolide moiety were obtained in excellent yields (up to 97%) and high enantioselectivities (up to 96% ee).