Cathode Material Determines Product Selectivity for Electrochemical C−H Functionalization of Biaryl Ketoximes

The synthesis of polycyclic N‐heteroaromatic compounds and their corresponding N‐oxides has been developed through electrochemical C−H functionalization of biaryl ketoximes. The oxime substrates undergo dehydrogenative cyclization when a Pt cathode is used, resulting in unprecedented access to a wide range of N‐heteroaromatic N‐oxides. The products of the electrosynthesis are switched to the deoxygenated N‐heteroaromatics by employing a Pb cathode through sequential anode‐promoted dehydrogenative cyclization and cathodic cleavage of the N−O bond in the initially formed N‐oxide.