Direct electrochemical difluorination and azo-fluorination of gem-difluorostyrenes

Herein, a direct electrolysis protocol for the chemo- and regio-selective difluorination, azo-fluorination, and fluoro-alkoxylation of gem-difluorostyrenes under mild conditions is demonstrated. The reaction enables the selective synthesis of a distinct type of long-chain perfluoroalkyl aromatics involving Et3N3HF as the fluorine source with/without other nucleophiles. The reaction exhibits good functional group tolerance, and is amenable to gram-scale synthesis. Moreover, an electrochemical reduction of the benzyl C-F bond was also achieved.