Selective Electrochemical Oxygenation of Alkylarenes to Carbonyls.

An efficient electrochemical method for benzylic C(sp)-H bond oxidation has been developed. A variety of methylarenes, methylheteroarenes, and benzylic (hetero)methylenes could be converted into the desired aryl aldehydes and aryl ketones in moderate to excellent yields in an undivided cell, using O as the oxygen source and lutidinium perchlorate as an electrolyte. On the basis of cyclic voltammetry studies, O labeling experiments, and radical trapping experiments, a possible single-electron transfer mechanism has been proposed for the electrooxidation reaction.