An Electrochemical Oxo‐amination of 2H‐Indazoles: Synthesis of Symmetrical and Unsymmetrical Indazolylindazolones

We have established a supporting‐electrolyte free electrochemical method for the synthesis of indazolylindazolones through oxygen reduction reaction (eORR) induced 1,3‐oxo‐amination of 2H‐indazoles where 2H‐indazole is used as both aminating agent as well as the precursor of indazolone. Moreover, we have merged indazolone and indazole to get unsymmetrical indazolylindazolones through direct electrochemical cross‐dehydrogenative coupling (CDC). This exogenous metal‐, oxidant‐ and catalyst‐free protocol delivered a number of multi‐functionalized products with high tolerance of diverse functional groups.