Heterogeneous catalyzed aryl–nitrogen bond formations using a valine derivative bridged metal–organic coordination polymer

A new 1D macrocyclic copper(II) coordination polymer, [CuL2] (1, L = N-(4-pyridyl)-D,L-valine), based on a valine derived ligand was synthesized and characterized by single-crystal X-ray diffraction studies. The catalytic experiments showed that compound 1 was an efficient catalyst for the cross-coupling reaction of arylboronic acids with imidazole in the absence of additional additives. The crystal structure analysis of 1 suggested that the vacant axial coordination position of the copper(II) atoms played a very important role in the efficient catalytic transformation process.