Direct Csp2−H difluoromethylation of heterocycle by K2S2O8

We reveal here a novel and efficient transition-metal-free C(sp2)–H oxidative difluoromethylation of heterocycle. It uses stable and nontoxic NaSO2CF2H as difluoromethyl source and potassium persulfate as oxidant without the need for metal catalyst. Significantly, the reaction affords difluoromethyl heterocycles in moderate to good yields with a broad substrate tolerance.