Copper‐Catalyzed Cyclization of Aryl Amines and Aryldiazonium Salts under Air: Access to N ‐2‐Aryl‐Naphthotriazoles

A catalytic and step economic protocol for the construction of N ‐2‐aryl‐naphthotriazoles via copper‐catalyzed cyclization of aryl amines and aryldiazonium salts is reported. With dioxygen in the air as termial oxidants under copper catalysis, various N ‐2‐aryl‐naphthotriazoles were synthesized in high yields. Importantly, this protocol features the sufficient inhibition of the classic C‐N 2 bond cleavage process of aryldiazonium tetrafluoroborates under copper catalysis and the undesired dehydrogenative coupling of aryl amines under oxidative conditions. Preliminary mechanistic studies indicated that a radical procedure might not be involved in this transformation. In addition, simple decoration of the obtained compounds delivers novel and attractive tetraphenylethylene moiety containing N ‐2‐aryl‐naphthotriazole derivatives.