Photoredox-Coupled F-Nucleophilic Addition: Allylation of gem-Difluoroalkenes.

A novel strategy for the expedient construction of CF3 -embeded tertiary/quarternary carbon centers was developed by taking advantage of photoredox catalysis. Thanks to a key step of single-electron oxidation, electron-rich gem-difluoroalkenes, which otherwise are essentially reluctant towards F-nucleoplilic addition, now readily participate in this fluoroallylation reaction. Furthermore, this strategy provides an elegant example for the generation, as well as functionalization, of α-CF3 -substituted benzylic radical intermediates using cheap and readily available starting materials.