Photocatalytic <i>In Situ</i> Amination of the Migrating Aryl Group: Rapid Access to 4-Aminated Benzenepropanamides

Aryl migration-induced difunctionalization of alkenes is a fascinating strategy for increasing the molecular complexity via the simultaneous formation of two chemical bonds across the C–C double bond. Despite the significant advances in this area, the in situ functionalization of the migrating aryl ring remains elusive due to the incompatibility between the conventional arene C–H functionalization strategy and the aryl migration process. Herein, we disclose the photocatalytic in situ amination of the migrating aryl ring in which an aryl ring is aminated and migrated within a single step, providing rapid access to valuable 4-aminated benzenepropanamide scaffolds. Such transformations enable the formation of an additional chemical bond on the migrating aryl ring beyond those two formed on the alkene carbons, significantly increasing the flexibility of the aryl migration strategy and improving the migration efficiency for the aminated aryl ring. The energy transfer catalytic cycle between the photosensitizer and the bifunctional reagents plays a pivotal role in combining the aryl migration process with the emerging radical-based arene remote C–H amination step. Experimental mechanistic studies support the proposed reaction pathway. The power of this protocol was demonstrated by the functionalization of pharmaceutically relevant molecules, the efficient synthesis of bioactive molecule analogs, and antibacterial activity investigations.