Regioregular head-to-tail poly(alkyl thiophene-3-carboxylates) have been prepared by very careful formation of the mono-Grignard reagent from alkyl 2,5-dibromothiophene-3-carboxylates (-40 °C, 1 h) followed by nickel-catalyzed polymerization. The spectral properties are reported along with the molecular weights.
Grignard reactions - cross-coupling - regioselectivity - polymers - thiophenes - esters