Phenyl(trifluoroethyl)iodonium-triflate-initiated ring-opening polymerization of tetrahydrofuran

A catalyst- and additive-free ring-opening polymerization of tetrahydrofuran initiated by phenyl(trifluoroethyl)iodonium triflate ([PhICH2CF3][OTf]) without using photo-irradiation is developed. The reaction proceeded at room temperature or elevated temperature to form CF3CH2-terminated polytetrahydrofuran in good yields and with different Mn(NMR) values. Phenyl(trifluoroethyl)iodonium triflate was evidenced as a much powerful mediator for cationic ring-opening polymerization of THF in comparison with other commonly used initiators. The temperature, concentration of [PhICH2CF3][OTf], and reaction time had a significant influence on both yield and number-average molecular weight of the polymerized product. This reaction provided an interesting synthetic route to novel polytetrahydrofuran bearing a trifluoroethyl end group.