Electrochemical Metal-Free Functionalization of ArCF3: Efficient Construction of C-S, C-Se, C-D, C-H, and C-C Bonds

Abstract

Herein, we report an innovative metal-free catalytic electrochemical defluorination method for constructing C-S, C-Se, C-D, C-H, and C-C bonds. This approach offers excellent versatility, starting from simple trifluoroarylbenzene as a starting material and enabling coupling with disulfides and diselenides, thiols, silyl thioethers, and sulfonyl thioethers, which greatly extends the substrate range compared to conventional methods. Furthermore, variation of the solvent allows for controlled defluorofunctionalization, enabling hydrodefluorination (ArCF2H), deuterodefluorination (ArCF2D), complete hydrogenation (ArCH3), and complete deuteration (ArCD3). The deuterodefluorination proceeds with a high deuterium incorporation ratio. By employing a continuous flow reactor system, we have succeeded in expanding the reaction process while halving the reaction time, increasing productivity and practical applicability. This green synthetic protocol features multiple advantages including catalyst-free conditions, ambient temperature operation, and high atom economy, effectively avoiding the environmental concerns associated with transition metal catalysts. Particularly noteworthy is its excellent functional group tolerance and chemoselectivity, which enables precise molecular editing of fluorinated compounds.