Copper(I) acetate-catalyzed azide-alkyne cycloaddition for highly efficient preparation of 1-(pyridin-2-yl)-1,2,3-triazoles.

A highly efficient copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) of 6-substituted tetrazolo[1,5-a]pyridines was developed for the preparation of 1-(pyridin-2-yl)-1,2,3-triazoles by simply using copper(I) acetate as a catalyst. The in situ formed HOAc played important dual roles and an activation of 2-azidopyridine-copper(I) complex was observed.