Copper(II)-Catalyzed Aerobic Oxidative Synthesis of Substituted 1,2,3- and 1,2,4-Triazoles from Bisarylhydrazones via C–H Functionalization/C–C/N–N/C–N Bonds Formation

An unprecedented copper­(II)-catalyzed aerobic oxidative
synthesis
of 2,4,5-triaryl-1,2,3-triazoles and 1,3,5-triaryl-1,2,4-triazoles
from bisarylhydrazones as the common starting precursor has been achieved
via cascade C–H functionalization/C–C/N–N/C–N
bonds formation under mild reaction conditions. One of the enthralling
outcomes of this strategy is the copper­(II)-catalyzed room temperature
C–H functionalization/C–N bond formation in presence
of air, which has been accomplished during the synthesis of substituted
1,2,4-triazoles. This new class of compounds could give prospective
luminescence as an iconic component in the area of pharmaceutical
and biological sciences. The intermediates for both the processes
have been isolated to elucidate the mechanistic scenario.