Photochemical dehalogenation mediated by macrocyclic nickel(II) complexes

A new photochemical dehalogenation system mediated by macrocyclic nickel(II) complexes was developed. Using this system, which consists of a macrocyclic nickel(II) complex catalyst, triethanolamine (TEOA) as a sacrificial reductant, and the ruthenium complex [Ru(bpy)3](ClO4)2 as a photosensitizer, catalytic debromination of 1-bromo-4-t-butylbenzene in acetonitrile was effectively carried out. The catalytic capabilities of various macrocyclic nickel(II) complexes in debromination reactions were also elucidated.