Some mechanistic aspects of a nickel-catalyzed electrochemical cross-coupling between aryl halides and substituted chloropyridazines

The nickel-2,2'-bipyridine catalyzed electrochemical cross-coupling reaction between an aryl halide and a chloropyridazine was investigated by an electrochemical study The electrochemical behavior of the divalent nickel complex is affected by the presence of pyridazine rings which act as co-ligands of nickel Cyclic voltammetry indicates that the cross-coupling reaction involves first a rapid oxidative addition of the chloropyridazine on the electrogenerated zerovalent nickel complex. The coupling product is then obtained by reaction with the aryl halide. (C) 2010 Elsevier Ltd. All rights reserved.