6,6′-Dimethyl-2,2′-bipyridine-4-ester: A pivotal synthon for building tethered bipyridine ligands

Bifunctional Gd(III) and Tb(III) chelates based on a pyridine–bis(iminodiacetate) platform, suitable optical probes and contrast agents for magnetic resonance imaging

“…In this direction, we decided to use a PMN tetraacetic acid chelator substituted by a carbomethoxy/carboxylic acid group on 4‐position of the pyridine ring as a bifunctional chelating agent ( 2 , Scheme ). This aromatic functionality is amenable to covalent biological coupling, directly or through the use of heterobifunctional cross‐linking reagents . Moreover, this strategy avoids the unsymmetrical functionalization of the chelating iminodiacetate moiety involving tedious synthetic protocols and low yields .…”

Selective synthesis of mono- and distannylpyridines from chloropyridinols via an SRN1 mechanism

“…For example, much supramolecular architectures are based on ligands synthesized through a Stille-type carbonecarbon bond-forming reaction [5]. This reaction has been widely employed owing to its versatile nature, great functional group toleration and better yields.…”

“…This fact diminishes the yield of purified distannylated pyridines 5. The IR spectra of the esters present characteristic absorptions at 1030, 1155e1164, 1183e1214, and 1265e1274 cm À1 .G.F.…”

Synthesis and Properties of Sodium and Europium(Ⅲ) Cryptates Incorporating the 4,4'-Substituted-2,2'-bipyridine Units

“…Luminescent rare earth (RE) complexes have attracted much attention because of the diversity in crystal structures and biological applications in fluorescent sensors, labels, catalysts and magnetism. [1] Bipyridine groups are often used in the syntheses of metal ion complexes due to the chelation effect and the π-accepting ability of these moieties, [2] and these metal-bipyridine complexes were found various applications in many chemistry areas including catalysis, electrochemistry, drug and so on. [3] In recent years, 2,2'-bipyridine unit and its derivatives are used to the synthesis of macrocyclic ligands and their RE metal complexes, [4] and the bipyridine unit serves both as a chelating subunit and as an antenna chromophore in these complexes.…”