Montmorillonite KSF clay supported CuO nanoparticles efficiently catalyzes one-pot aromatic azidonation of aryl boronic acids followed by regioselective azide–alkyne 1, 3- dipolar cycloaddition (CuAAC) reaction producing corresponding 1-aryl-1, 2, 3-triazole derivatives at room temperature in excellent yields without use of any additives. Investigations on mechanism of CuAAC revealed that sodium azide, which is used as ...