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Polymerization of optically active 2-fluorophenyl-4-fluorophenyl-2-pyridylmethyl methacrylate with anionic and radical initiators: Stereospecificity and helix-sense selection
Authors:Jian Wu  Tamaki Nakano  Yoshio Okamoto
Abstract:Almost optically pure (+)- and (−)-2-fluorophenyl-4-fluorophenyl-2-pyridylmethyl methacrylate (2F4F2PyMA) monomers were obtained by HPLC resolution of the racemic monomer and polymerized with the use of anionic and free-radical initiators. Helix-sense selectivity during the polymerization seemed to be governed mainly by the chirality of the monomer itself, and the polymers obtained by using the complex of N,N′-diphenylethylenediamine monolithium amide with (S)-(+)-1-(2-pyrrolidinylmethyl)pyrrolidine (PMP) in toluene at −78°C appeared to possess single-handed helical conformation (+)-poly[(−)-2F4F2PyMA], [α]365 + 1510°; (−)-poly[(+)-2F4F2PyMA], [α]365 − 1610°]. The single-handed helical (+)-poly[(−)-2F4F2PyMA] and (−)-poly[(+)-2F4F2PyMA] obtained with the PMP complex exhibited better chiral recognition ability toward trans-stilbene oxide compared with the single-handed helical poly(rac-2F4F2PyMA) prepared previously. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2645–2648, 1999
Keywords:helix  asymmetric polymerization  2-fluorophenyl-4-fluorophenyl-2-pyridylmethyl methacrylate  chiral recognition
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