Manganese(III)-mediated direct Csp2-H radical trifluoromethylation of coumarins with sodium trifluoromethanesulfinate

Mn(OAc)(3)-mediated direct C-sp2-H radical trifluoromethylation of coumarins with CF3SO2Na (Langlois reagent) to afford selective 3-trifluoromethyl coumarins in moderate to good yields is described. This methodology can also be applied to the trifluoromethylation of quinolinones and pyrimidinones.