Electrochemical cobalt-catalyzed C-H or N-H oxidation: a facile route to synthesis of substituted oxindoles.

Two comparable protocols for the electrochemical cobalt-catalyzed C-H/N-H oxidation have been exploited for the synthesis of substituted oxindoles via radical pathways. The electrochemical cobalt-catalyzed system was demonstrated to be efficient and eco-friendly and avoided the use of stoichiometric oxidants to afford the arylation or alkylation products in good yields at room temperature.