A new binuclear Ni(II) complex, an effective A-coupling catalyst in solvent-free condition.

A newly binuclear nickel(II) complex, [Ni(en)(ox)](ClO) () (where en = ethylenediamine, and ox = oxalate), has been isolated from a reaction of NiCl·6HO, ethylenediamine, ammonium oxalate and sodium perchlorate in water and its crystal structure has been determined by X-ray crystallography and infra-red techniques. Compound was successfully employed to promote the one-pot reaction of aldehydes, amines and acetylenes for the construction of corresponding propargylamines under solvent-free media with fine yields. Further studies reveal this catalytic system can be refreshed and used again in five runs.