A theoretical study of the relationship between the electrophilicity ω index and hammett constant σp in [3+2] cycloaddition reactions of aryl azide/alkyne derivatives

Abstract

The relationship between the electrophilicity ω index and the Hammett constant σp has been studied for the [2+3] cycloaddition reactions of a series of para-substituted phenyl azides towards para-substituted phenyl alkynes. The electrophilicity ω index-a reactivity density functional theory (DFT) descriptor evaluated at the ground state of the molecules-shows a good linear relationship with the Hammett substituent constants σp. The theoretical scale of reactivity correctly explains the electrophilic activation/deactivation effects promoted by electron-withdrawing and electron-releasing substituents in both azide and alkyne components.