Enhanced Clickability of Sterically-Hindered Aryl Azides

Abstract

We discovered that the click reaction of doubly ortho-substituted aromatic azide with alkyne proceeds faster than that of unsubstituted phenyl azide, inspite of the steric hindrance. The kinetic study of click reaction using various azides has shown clear relationship between bulkiness of the substituents and the reaction rate. Along with the results of spectroscopic analyses and density functional theory (DFT) calculations, we will discuss the accelerating effect elicited by the bulky substituents of aromatic azide in the click reaction.