Regioregular Polymerization of Fluorine-Containing Epoxides

Epoxides bearing fluorine (F)-containing substituents on ethylene oxide were polymerized under mild conditions to give regioregular polyethers. To alleviate the electron-withdrawing effect of fluoroalkyl or fluoroaryl groups, more than one unit of methylene spacer had to be introduced into a side chain for regioregular polymerization with high activity. Optically active isotactic polyethers were obtained from enatiopure monosubstituted ethylene oxides as a result of regioselective ring opening via successive cleavage of the less substituted carbon−oxygen bond. Obtained optically active isotactic polyethers were investigated through circular dichroism (CD) spectra or optical rotatory dispersion (ORD) spectra in solution states. As a result, no evidence for the formation of helical conformation was detected in both the F-substituted and the corresponding hydrogen (H)-substituted optically active isotactic polyethers.