An expeditious approach to a variety of dimeric 2-oxindoles with a C-3/C-5′ linkage sharing an all-carbon quaternary center at the pseudobenzylic position has been developed
A highly enantioselective α-amination of 3-substituted oxindoles with azodicarboxylates catalyzed by amino acids-derived chiral phosphine catalysts is reported. The corresponding products containing a tetrasubstituted carbon center attached to a nitrogen atom at the C-3 position of the oxindole were obtained in high yields and with up to 98% ee.