Copper-Catalyzed Regioselective sp³ C–H Azidation of Alkyl Substituents of Indoles and Tetrahydrocarbazoles

An efficient regioselective sp³ C–H azidation is developed using CuBr as the catalyst and Zhdankin azidoiodinane as the “N₃” source. Under simple and mild reaction conditions, the azido group could be successfully incorporated into the sp³ C–H alkyl substituents of indoles and tetrahydrocarbazoles.