Synthesis of Substituted Oxindoles from α-Chloroacetanilides via Palladium-Catalyzed C−H Functionalization

A novel method for the synthesis of oxindoles is described. In the presence of catalytic palladium acetate and 2-(di-tert-butylphosphino)biphenyl, alpha-chloroacetanilides are converted to oxindoles in good to excellent yields with high functional group compatibility using triethylamine as a stoichiometric base. The cyclization is highly regioselective, obviating the need for prefunctionalized arenes. Plausible mechanistic pathways for the reaction are discussed.