Functionalized 2,2′-bipyridines and 2,2′:6′,2"-terpyridines via Stille-type cross-coupling procedures

Stille-type cross-coupling procedures are utilized in order to prepare a variety of fanctionalized 2,2'-bipyridines and 2,2':6',2"-terpyridines. Such N-heterocyclic compounds are of great interest as chelating ligands for transition-metal ions in the field of supramolecular chemistry. Various mono- and disubstitued 2,2'-bipyridines were synthesized in high yields and multigram scales using a modular design principle. The terpyridines may be functionalized in one step with different substituents at the outer pyridine rings and at the 4'-position of the centered ring, leading to multifunctionalized compounds. The initially obtained methyl ester and ethyl ester groups can be simply converted into bromomethyl and hydroxymethyl groups which allow further functionalization reactions.