Formation of diazoketones and azines by improved oxidation of ketohydrazones using Cu(acac)2 as a catalyst

Article abstract of DOI:10.1016/S0040-4039(00)77176-0

An efficient Cu(acac)₂-catalyzed oxidation of ketohydrazones afforded the corresponding α-diazeketones or ketazines in high yields depending on the reaction conditions. However, the reaction of benzophenone hydrazone gave benzophenone azine without affording diphenyldiazomethane. The formation of azines is explained by intermediacy of carbenoid generated by the Cu(acac)₂-catalyzed decomposition of diazo compounds.