Photoredox-catalyzed halotrifluoromethylations of alkynes with triethylammonium halides: synthesis of tetrasubstituted alkenes containing CF3 and halogens

Abstract

The difunctionalization of alkynes with fluorine and trifluoromethyl groups is enabled by photoredox catalysis under mild reaction conditions. Herein, various alkyne derivatives were converted into difunctionalized alkenes with high functional group tolerance using triethylamine trihydrofluoride (Et₃N·3HF) and a photoredox catalyst. This method can be extended to the production of chloro- and bromo-trifluoromethylated alkynes with triethylammonium chloride and bromide, respectively. This strategy provides a synthetic platform that can be used to obtain halotrifluoromethylated alkenes, and for the late-stage functionalization of bioactive molecules derived from natural products.