The copper()-catalyzed and oxidant-promoted regioselective C-2 difluoromethylation of indoles and pyrroles

A novel and efficient approach for the highly selective C-2 difluoromethylation of indole derivatives was developed by using sodium difluoromethylsulfinate (HCF 2 SO 2 Na) as the source of difluoromethyl groups and a Cu( ii ) complex as the catalyst. Various substrates were well tolerated in this transformation and the desired products were obtained in moderate to good yields. Moreover, the late-stage C-2 difluoromethylation of bioactive molecules containing an indole ring was achieved in good yields. Generally, this reaction features excellent functional group compatibility, broad substrate scope and excellent C-2 selectivity. A novel and efficient approach for the highly selective C-2 difluoromethylation of indole derivatives was developed by using sodium difluoromethylsulfinate (HCF 2 SO 2 Na) as the source of difluoromethyl groups and a Cu( ii ) complex as the catalyst.