A Dehydrogenative Homocoupling Reaction for the Direct Synthesis of Hydrazines from N-Alkylanilines in Air

A copper-catalyzed N-N bond-forming reaction was performed by a dehydrogenative homocoupling of N-alkylanilines, affording N, N'-dialkyl-N, N'-diphenylhydrazines in 72-88% yields. This new strategy has the advantages of direct synthesis from N-alkylanilines, using air as the oxidant, convenient manipulations, mild reaction conditions and moderate to good yields. A possible mechanism by coordination and reductive elimination has been proposed.