A Synthesis of 1<i>H</i>‑Indazoles via a Cu(OAc)₂‑Catalyzed N–N Bond Formation

A facile synthesis of 1<i>H</i>-indazoles featuring a Cu­(OAc)₂-catalyzed N–N bond formation using oxygen as the terminal oxidant is described. The reaction of readily available 2-aminobenzonitriles with various organometallic reagents led to <i>o</i>-aminoaryl N–H ketimine species. The subsequent Cu­(OAc)₂-catalyzed N–N bond formation in DMSO under oxygen afforded a wide variety of 1<i>H</i>-indazoles in good to excellent yields