A Photoredox Complex Catalyzed Direct Trifluoromethylation / Chlorination of Alkynes

Han et al. have reported the direct trifluoromethylation / chlorination of alkynes through the blue LED and Ir(ppy)₃ complex-catalyzed photoredox reaction using trifluoromethanesulfonyl chloride. According to their report, this photoredox reaction can be performed using aryl group substituted alkynes under mild conditions giving the regioselectively trifluoromethyl and chloro groups-substituted tetrasubstituted alkenes. In this reaction, a trifluoromethyl radical and a chloride ion are generated from trifluoromethanesulfonyl chloride by the photoredox catalyst. The subsequent addition to aryl alkynes affords the geminal chloro and aryl groups-substituted alkenes regioselectively. Obtained alkenes can be applied to the coupling reaction leading to 1,1-diarylalkenes. This synthetic approach is expected to be used for the study of material science.