Cu(II)-mediated oxidative dimerization of 2-phenylpyridine derivatives

A Cu(II)/I-2-mecliated C-H bond activation is described. A variety of 2-phenylpyridine derivatives are oxidatively dimerized at the ortho-position of the phenyl ring in which a net loss of two hydrogen atoms results ill [lie formation of a biaryl compound via a double C-H activation/C-C bond-forming process. Moderate functional group tolerance was observed on both the aryl and the pyridyl rings. A single electron transfer (SET) or electrophilic metalation process for iodination followed by Ullmann Coupling Of the intermediate iodinated product is proposed as the operating mechanism for the dimerization process. (C) 2008 Published by Ekevier Ltd.