6-(Arylvinylene)-3-pyridinylboronic esters. Part 1: Versatile building blocks for conjugated chromophores via Suzuki cross-coupling

This paper describes a general approach for the synthesis of conjugated 6,6′-disubstituted-3,3′-bipyridine chromophores. As preliminary results, 6-(4-hexyl-2-thienylvinylene)-5-methyl-3-bromopyridine, 6-(4-ethanol-2-thienylvinylene)-5-methyl-3-bromopyridine, and the corresponding 3-pyridinylboronic esters have been prepared. Coupled by Suzuki reaction, they gave the conjugated chromophores (I) and (II) in high yields and multigram scales.