Palladium-Catalyzed Intramolecular 5-exo-dig Hydroarylations of N-Arylpropiolamides:Thermodynamics-Controlled Stereoselective Synthesis of 3-Methyleneoxindoles

摘要

Palladium-catalyzed intramolecular hydroarylation of N-arylpropiolamides has been developed for the stereoselec-tive synthesis of 3-(monosubstituted methylene)oxindoles. Inthe presence of Pd(OAc)2 and dppf, a variety of N-arylpro-piolamides successfully underwent the intramolecular hydro-arylation reaction to afford the corresponding 3-(mono-substituted-methylene)oxindoles in moderate to excellentyields. It is noteworthy that the stereoselectivity of the reactioncan be controlled by varying the reaction temperature.