Effect of divalent metals was studied in the cross-coupling polymerization of thiophenes leading to head-to-tail-type poly-3-hexylthiophene. Deprotonation of the C–H bond at the 5-position of 2-halo-3-hexylthiophene by LDA followed by metal exchange was carried out in one pot and following addition of nickel catalyst underwent polymerization. One-shot reaction involving deprotonation/transmetalation/ cross coupling polymerization was also examined with manganese(II) chloride and nickel(II) catalyst.
Key words
deprotonative metalation - poly(3-hexylthiophene) - group II metals - nickel catalyst - one-shot reaction