Synthesis of Oligo(thienylene-vinylene) by Regiocontrolled Deprotonative Cross-Coupling

Concise synthesis of oligo(thienylene-vinylene) with a head-to-tail type structure is achieved by regioselective deprotonative coupling of 3-hexylthiophene. The palladium catalyzed reaction of 3-hexylthiophene with (E)-2-(2-bromoethenyl)-3-hexylthiophene takes place to afford head-to-tail type trans-1,2-dithienylethene. Further extension of a vinylthiophene unit is similarly performed in an iterative manner.