Visible-Light-Induced Direct Csp2-H Radical Trifluoroethylation of Coumarins with 1,1,1-Trifluoro-2-iodoethane (CF3CH2I).

Herein, we developed the first visible-light-induced direct Csp2-H radical 2,2,2-trifluoroethylation of coumarins with commercially available and cheap reagent CF3CH2I at room temperature. This transformation proceeded smoothly under mild conditions and showed excellent functional group compatibility. The synthetic value of the protocol was also demonstrated by the successful functionalization of several pharmaceuticals.