Copper(II) Complexes Supported by Bis(imino)pyridine Ligands: Synthesis and Catalysis on Azide‐Alkyne Click Reactions

Abstract

AbstractThe synthesis, characterization and catalytic activity of copper(II)‐bis(imino)pyridine pincer complexes were described. The copper(II) complexes (2 a and 2 b) were synthesized by the reaction of 2,6‐bis(imino)pyridine ligands with CuCl2 ⋅ 2H2O in methanol as a solvent. The copper(II) complexes were fully characterized by IR, UV‐Visible, Mass spectroscopy and elemental analysis. The copper(II) complexes 2 a and 2 b showed excellent catalytic activity towards azide‐alkyne cycloaddition (Click reaction) in water and produced regioselective product of 1,4‐disubstituted‐1,2,3‐triazoles. The copper(II) complex (2 b) with electron withdrawing CF3 group exhibited comparatively higher catalytic activity in azide‐alkyne cycloaddition reactions and produced up to 93 % of yield with 0.05 mol % of the catalyst loading.