Study on the ArI-catalyzed intramolecular oxy-cyclization of 2-alkenylbenzamides to benzoiminolactones.

A new intramolecular oxy-cyclization of 2-alkenylbenzamides catalyzed by ArI has been developed. This protocol is highlighted by its metal-free catalytic system and extremely short reaction time, providing efficient and straightforward access to various benzoiminolactones in good to excellent yields. Interestingly, a regioselective transformation occurred when using two different reaction systems. Mechanistic studies suggested that mCPBA acts as both oxidant and ligand at the IIII center, and the Lewis acid BF3 accelerated ligand exchange and reductive elimination in the catalytic process.