Synthesis of {15-benzyloxy-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene}nickel(II) perchlorate and its analogs, and their catalytic behavior in reductive debromination of 1-bromo-4-tert-butylbenzene

New nickel(II) complexes with macrocyclic ligands bearing benzyloxy [(5), (9)], 2-methylbenzyloxy (7), 3-methylbenzyloxy (8), and hydroxy (6) groups on the pyridine ring have been synthesized. Structures of the hydroxy substituted macrocyclic ligand (L-OH·3HCl·H2O), and the benzyloxy substituted ligand (L-OBn·3HCl) and its nickel(II) complex (5), as well as an analogous Ni(II) complex (8), have been revealed by X-ray crystallography. Their catalytic capabilities in the reductive debromination of 1-bromo-4-tert-butylbenzene have been elucidated, which has revealed that the pyridine ring can be a suitable position for the introduction of functional groups while maintaining the catalytic capabilities of the nickel(II) complexes.

Graphical abstractNew nickel(II) complexes with macrocyclic ligands bearing benzyloxy, 2-methylbenzyloxy, 3-methylbenzyloxy, and hydroxy groups on the pyridine ring have been synthesized. Structures of the hydroxy substituted macrocyclic ligand (L-OH·3HCl·H2O), and the benzyloxy substituted ligand (L-OBn·3HCl) and its nickel(II) complex have been revealed by X-ray crystallography. Their catalytic capabilities in the reductive debromination of 1-bromo-4-tert-butylbenzene have been elucidated.Figure optionsDownload full-size imageDownload as PowerPoint slide