Photoredox Catalyzed Synthesis of gem -Difluoroalkenes and Monofluorinated Cyclooctenes via 1,5-HAT Process.

gem -Difluoroalkenes and monofluorinated cycloalkenes have emerged as basic structural units in a variety of bioactive molecules and natural products. Thus, developing straightforward and efficient methods for synthesizing fluorinated alkene compounds is of considerable significance. Herein, we disclose a visible-light-induced defluorination of 2-trifluoromethyl-1-alkene via a 1,5-HAT process using N -alkoxyphtalimides as both radical precursor and potential nucleophile. The mild and stepwise reaction leads to a variety of structurally diverse gem -difluoroalkenes and monofluorinated cyclooctenes with high efficiency, respectively.