Synthesis of 2-Aryl-1,2,3-triazoles by Oxidative Cyclization of 2-(Arylazo)ethene-1,1-diamines: A One-Pot Approach

A one-pot approach for the synthesis of 2-aryl-5-amino-1,2,3-triazoles is reported. This approach involves a tandem nucleophilic addition of alkylamines to hydrazonoyl cyanides and in situ oxidative cyclization of the resulting 2-(arylazo)ethene-1,1-diamines in the presence of copper(II) acetate and air. The described one-pot procedure is characterized by good yields, excellent selectivity, methodical simplicity, and uses readily available chemicals. This method was applied to the gram-scale synthesis of 2-aryl-1,2,3-triazoles. A new one-pot synthesis of functionalized 2-aryl-1,2,3-triazoles has been developed. The developed procedure is efficient, safe and applicable to a broad scope of substrates. In addition, tethis approach has a higher atom economy factor and allows for the synthesis of new 2-aryl-1,2,3-triazoles that were not previously accessible using reported methods.