Metal‐Free Catalyzed Cyclization of N ‐Methoxybenzamides to Construct Quaternary Carbon‐Containing Isoindolinones

Main observation and conclusion Through the intramolecular cyclization of N ‐methoxybenzamides, a simple and efficient method for constructing valuable isoindolinones under metal‐free conditions was developed. The reaction was featured by employing low‐cost catalyst, simple operation, 100% atomic economy and excellent regioselectivity. Moreover, a detailed computational study on the reaction system has been performed to clarify the mechanism. This protocol tolerated a variety of functional groups and provided a metal‐free protocol for the synthesis of chromane‐ or tetrahydroquinoline‐fused isoindolinones in good yields.