Computational study on regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles using quantum chemistry methods

Synthesis of 1,4-disubstituted 1,2,3- triazoles in the presence of SMI-CuI catalyst has been modeled by means of density functional theory in terms of structural and thermochemical aspects in the gas phase and also in the presence of three different solvents; ethanol, acetonitrile and water via polarized continuum model. Based on the calculated thermodynamical properties of the reaction, we have shown that the production of 1,4 disubstituded 1,2,3-triazole is more favourable thermodynamically. Moreover, from thermodynamic point of view, we have determined acetonitrile as more appropriate solvent.
In the next step, the structural and energetic properties of the corresponded transition states to 1,4 and 1,5 disubstituted 1,2,3-triazole products, considering SMI-CuI catalyst effect, were assessed to interpret the origins of regioselectivity. Additionally, we have analyzed the regioselective behavior of the synthesis electronically, based on the quantum theory of atoms in molecules calculations.