Copper‐Mediated Dual Cyclization of 2‐(Alkynylaryl)Anilines with 2‐Formylbenzonitriles: Access to 3‐(1 H ‐Indol‐3‐Yl)Isoindolin‐1‐Ones

Herein, we report a novel strategy for the synthesis of 3‐(1 H ‐indol‐3‐yl)isoindolin‐1‐ones via copper‐mediated dual cyclization of 2‐(alkynylaryl)anilines with 2‐formylbenzonitriles. Mechanistic studies reveal that the isoindolinone core is preferentially formed, and this transformation involves an unexpected isoindolinone migration process. This approach features high atom economy, broad substrate scope, and the use of inert nitrile as the nitrogen source for isoindolinone. Moreover, the practicality of this method is demonstrated by gram‐scale synthesis and late‐stage derivatizations.