Palladium-Catalyzed Carbonylative Synthesis of N-Acetyl Benzoxazinones

A palladium-catalyzed intramolecular carbonylation reaction for the synthesis of N-acetyl benzoxazinones has been achieved for the first time. To avoid the using of toxic and flammable CO gas, formic acid was utilized as the CO source here. This carbonylative process is conducted under mild reaction conditions with high reaction efficiency. A variety of the desired N-acetyl benzoxazinone products were obtained in moderate to excellent yields with very good functional group compatibility. The presents of acid anhydride holds two roles here: formic acid activator and acyl source.