SYNTHESIS AND POLYMERISATION OF ETHYNYLTHIOPHENES AND ETHYNYLFURANS CONTAINING TRIFLUORMETHYL GROUPS

Article abstract of DOI:10.1016/S0022-1139(00)82929-2

Fluorination of thiophenedicarboxylic acid with sulfur tetrafluoride in the presence of anhydrous hydrogen fluoride provided mono and bis(trifluoromethyl)thiophenes in moderate yields.Ethynylthiophenes and ethynylfurans containing trifluoromethyl groups were prepared via 2,2-dichloro-1-fluorovinyl compounds.In polymerizations using transitions metal catalysts, 3-ethynylthiophenes gave polymers in high yields, which were soluble in THF and/or fluorocompounds, while 2-ethynylthiophenes polymerized in low yields.In γ-ray induced polymerization, only 2,5-bis(trifluoromethyl)-3-ethynylthiophene afforded the corresponding polymers.Thermal decomposition temperatures of polymers obtained increased by introduction of the trifluoromethyl groups as well as the methyl groups.