Computational Study of Regioselective Synthesis of Triflylpyrazole by Cycloaddition Reaction between Diphenyl Hydrazonoyl Chloride and Phenyl Triflyl Acetylene

Abstract

The mechanism and regioselectivity of cycloaddition reaction between diphenyl hydrazonoyl chloride and phenyl triflyl acetylene as an electron-deficient dipolarophyl in acetonitrile at room temperature are theoretically investigated using density functional theory and solvent polarized continuum model. Two general mechanism, concerted and stepwise mechanism, have been proposed for this reaction. Each mechanism has two different paths and two possible products. The activation energies of pathways were calculated using quantum mechanical approach and compared with each other. An excellent agreement was observed between the previously reported experimental work and the theoretical approaches for regioselectivity of this reaction.