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

Abstract

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 I^III center, and the Lewis acid BF₃ accelerated ligand exchange and reductive elimination in the catalytic process.