Electrochemical regioselective reduction of α-keto amide with methanol as hydrogen source

Abstract

An efficient method of α-keto amides to α-hydroxy amides has been developed for the regioselective hydrogenation reduction. Under the assistance of electricity and methanol as both hydrogen source and solvent, KI and base participate in reaction to obtain various α-hydroxy amides (42 cases, up to 100%). The reaction is operationally simple (room temperature, air environment, undivided cell with constant current electrolysis), avoids the use of traditional reducing agents, is free from metal or transition-metal catalysts, and does not require organic ligands. CV experiments and control studies show that the reduction of α-keto amides employed a parallel paired electrolysis strategy. The substrate was reduced at the cathode, while KI undergoes oxidative reactions at the anode by easily losing electrons. Moreover, this reaction can tolerate high current densities and can be scaled up to the grams.