Pyridine-phosphinimine ligand-accelerated Cu(I)-catalyzed azide-alkyne cycloaddition for preparation of 1-(pyridin-2-yl)-1,2,3-triazole derivatives

A series of phosphinimine ligands were designed and used in the Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction of tetrazolo[1,5-a]pyridines and alkynes for the first time. By optimizing the reaction conditions, an efficient catalytic system (CuCl/2-PyCH2N=(PBu3)-Bu-t) was developed to give 1-(pyridin-2-yl)-1,2,3-triazole derivatives in moderate to excellent yields (46-98%).