Asymmetric anionic polymerization of (2-fluorophenyl)(4-fluorophenyl)(2-pyridyl)methyl methacrylate leading to a helical polymer

✍ Scribed by Jian Wu; Tamaki Nakano; Yoshio Okamoto

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 172 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19980915)36:12<2013::aid-pola6>3.0.co;2-y

✦ Synopsis

A novel racemic methacrylate, (2-fluorophenyl)(4-fluorophenyl)(2-pyridyl)methyl methacrylate 1 (2F4F2PyMA), was synthesized and polymerized with chiral complexes of N,N-diphenylethylenediamine monolithium amide (DPEDA-Li) with (0)-sparteine (Sp), (2 S, 3S)-(/)-2,3-dimethoxy-1,4-bis(dimethylamino)butane (DDB), and ( S)-(/)-1-(2-pyrrolidinylmethyl)pyrrolidine (PMP) in toluene at 078ЊC. The monomer showed higher resistance against methanolysis compared with triphenylmethyl methacrylate (TrMA) and several other analogues. In the asymmetric anionic polymerization of 2F4F2PyMA, PMP was found to be a more effective chiral ligand than DDB and Sp and gave quantitatively an optically active polymer with nearly perfect isotacticity. Enantiomer selection was observed in the polymerization of racemic 2F4F2PyMA with the chiral lithium complexes. Chiral recognition ability of the optically active poly(2F4F2PyMA) was examined by an enantioselective adsorption experiment.