A modular procedure for the synthesis of functionalised β-substituted terthiophene monomers for conducting polymer applications

An efficient modular strategy has been developed for the synthesis of β-functionalised terthiophene monomers using Suzuki–Miyaura and Wittig/Horner–Emmons chemistries. This paper discusses the problems encountered with converting the β-terthiophene aldehyde building block to the β-terthiophene phosphonium salt and the use of this material in a Wittig condensation. An improved strategy using the β-terthiophene phosphonate building block constructed via Suzuki–Miyaura coupling protocols was developed. We have synthesised and characterised a broad range of functionalised terthiophene materials that have been designed for specific end-use applications. The availability of these building blocks has dramatically increased access to a range of key monomers.