A chiral N ‐9‐Anth‐PyBidine‐Co(OAc) 2 complex catalyzed the kinetically controlled asymmetric Michael/alkylation reaction of 3‐chlorooxindoles with alkylidenemalononitriles to give gem ‐dicyano‐spirocyclopropyl oxindoles in a highly diastereo‐ and enantioselective manner. The reaction could be conducted as a three‐component coupling reaction of 3‐chlorooxindoles, aldehydes, and malononitrile, avoiding time and energy‐consuming synthesis of alkylidenemalononitriles. One of the cyano functionalities in the chiral gem ‐dicyano‐spirocyclopropyl oxindole could be converted to an amide by Pd(NO 3 ) 2 catalysis while retaining the optically active spirocyclopropane ring to afford a diversely functionalized spirocyclopropyl oxindole.
Saito et al. (Sun,) studied this question.