Efficient solid-phase synthesis of regioregular head-to-tail-coupled oligo(3-alkylthiophene)s up to a dodecamer

Solid-phase synthesis of isomerically pure head-to-tail-coupled (HT) oligo(3-hexylthiophene)s on chloromethylated polystyrene resin has been developed. Using novel sequences of iodination and Suzuki cross-coupling reaction, a series up to a dodecamer has been synthesized in high yield and purity. Removal of the conjugated oligomers from solid support as methyl esters, saponification and decarboxylation to the HT-coupled oligo(3-alkylthiophene)s could be effectively achieved.