Highly Enantioselective Synthesis of 3-Amino-2-oxindole Derivatives: Catalytic Asymmetric α-Amination of 3-Substituted 2-Oxindoles with a Chiral Scandium Complex.

The present new method for the α-amination of 3-substituted oxindoles with azodicarboxylates is catalyzed by a chiral Sc(OTf)3/N,N′-dioxide complex generated in situ to afford optically active 3-amino-2-oxindole derivatives in high yields and with excellent enantioselectivities.