Stille-Type Cross-CouplingAn Efficient Way to Various Symmetrically and Unsymmetrically Substituted Methyl-Bipyridines:  Toward New ATRP Catalysts

Various mono- and disubstituted 2,2'-bipyridines were synthesized in high yields and multigram scales utilizing Stille-type coupling procedures. The corresponding bromo-picoline and tributyltin-picoline building blocks were prepared from commercially available amino-picoline compounds. As first examples of metal complexes, 4,5'-dimethyl-2,2'-bipyridine was reacted with copper(II) and iron(II) ions and investigated as catalyst in ATRP.