K2S2O8‐Glucose‐Mediated Metal‐Free Oxidative Trifluoromethylation of Indoles with Langlois’ Reagent on the C2 Position

Abstract An efficient and regioselective trifluoromethylation method of indole at the C2 position with ecologically‐sound Langlois’ reagent (CF 3 SO 2 Na) under metal‐free conditions is described. K 2 S 2 O 8 in presence of glucose at room temperature has been utilized for the generation of CF 3 radicals from CF 3 SO 2 Na. The desired product can be obtained in good to excellent yields with a wide scope of substrate variability and gram scalability.