Two new copper(II) complexes with chelating N,O-type bidentate ligands: Synthesis, characterization, crystal structure and catalytic activity in azide-alkyne cycloaddition reaction

Tetra-coordinated copper(II) complexes, [CuL2] and [Cu(phox)(2)], were synthesized by reaction of 1-((4-bromophenylimino) methyl) naphthalen-2-ol, HL, and 2-(2'-hydroxyphenyl)-2-oxazoline, Hphox, ligands with copper acetate, respectively. The complexes were characterized using FT-IR spectroscopy, elemental analyses, and their solid state structures were confirmed by single crystal X-ray diffraction. The catalytic activity of the complexes was evaluated in one-pot azide-alkyne cycloaddition (AAC) click reaction in water without need of any additional agent. The [CuL2] complex showed high catalytic activity in this reaction and 1,2,3-triazole derivatives were produced in moderate to good yields. Crown Copyright (C) 2017 Published by Elsevier B.V. All rights reserved.