A Convenient Synthesis of (E)‐α‐Alkylidene‐γ‐lactams and (E)‐3‐Alkylideneoxindoles by Rhodium‐Catalyzed Intramolecular Hydroamidation.

Abstract Rhodium-catalyzed carbonylative cyclization without carbon monoxide was investigated. Cyclization of various formamides having alkynyl groups proceeded smoothly in the presence of Rh4(CO)12 to provide α-alkylidene-γ-lactams or 3-alkylideneoxindoles in moderate to good yields with high (E)-selectivity.