Copper-Catalyzed Synthesis of Indol-3-yl α-(Difluoromethyl)-α-(trifluoromethyl)carbinols: Construction of Difluoromethylated sp3 Carbon Centers.

An efficient copper-catalyzed synthesis of indol-3-yl α-(difluoromethyl)-α-(trifluoromethyl)carbinols is developed. The reaction proceeds in good to excellent yields through a Friedel-Crafts-type mechanism, and a variety of indoles with commonly occurring functional groups such as formyl, cyano, nitro, alkyloxide, and halogen are well tolerated. In addition, these carbinol products are readily transformed into diversified difluoromethylated dinitrile indol-3-yl derivatives. This strategy provides a general synthetic method for ready construction of difluoromethylated sp3 carbon centers.