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.