Skeleton Editing of Indenes With Metal Carbenes to Access 1,2‐Dihydronaphthalenes

ABSTRACT Single‐atom insertion reactions in cyclic scaffolds have garnered unprecedented attention in recent years. Despite significant advances, the direct skeleton editing of planar indene to yield three‐dimensional 1,2‐dihydronaphthalene via carbon atom insertion remains unknown. Herein, we report a silver‐catalyzed skeletal editing strategy that enables the direct insertion of a functionalized carbon atom into indenes, accessing the corresponding 1,2‐dihydronaphthalenes by trapping of an α‐trifluoromethyl arylcarbene generated from triftosylhydrazone. This transformation is operationally simple, conducted on a preparative scale, and affords products that are amenable to further derivatization. In addition, the first asymmetric single‐atom skeleton editing of indenes was accomplished by using a chiral dirhodium catalyst. Comprehensive experimental and computational studies were performed to provide detailed insights into the mechanistic pathway and the origin of enantioselectivity.