Abstract
| - 2,2‘-Bipyridine (bpy) and a series of dimethyl-2,2‘-bipyridines were synthesized from 2-bromopyridineand 2-bromomethylpyridines, respectively, using an electrochemical process catalyzed by nickelcomplexes. The method is simple and efficient, with isolated yields between 58 and 98% accordingto the structure. We first studied the influence of the presence and the position of the methyl groupon the yield, using N,N-dimethylformamide (DMF) or acetonitrile (AN) as the solvent, NiBr2bpyas the catalyst, and Zn as the sacrificial anode, in an undivided cell and at ambient temperature.On the basis of a better understanding of the reaction mechanism based on electroanalytical studies,we could improve the dimerization both by substituting the catalyst ligand (bpy) by the reagentitself, i.e., 2-bromomethylpyridine or 2-bromopyridine, and by using Fe instead of Zn as the sacrificialanode.
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