CuBr-Catalyzed Direct Indolation of Tetrahydroisoquinolines via Cross-Dehydrogenative Coupling between sp3 C−H and sp2 C−H Bonds

A novel and efficient C-C bond formation method was developed via the cross-dehydrogenative coupling (CDC) reaction of indoles and tetrahydroisoquinolines catalyzed by copper bromide in the presence of an oxidizing reagent, tert-BuOOH. The CDC reaction provides a simple and efficient catalytic method to construct indolyl tetrahydroisoquinolines via a combination of sp3 C-H bond and sp2 C-H bond followed by C-C bond formation.