Novel isolated,L‐amino acid‐ligated rhodium catalysts that induce highly helix‐sense‐selective polymerization of an achiral 3,4,5‐trisubstituted phenylacetylene |
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| Authors: | Hongge Jia Yongqiang Shi Liqun Ma Xuan Gao Yazhen Wang Yu Zang Jijun Peng Toshiki Aoki Masahiro Teraguchi Takashi Kaneko Toshio Masuda |
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| Affiliation: | 1. College of Materials Science and Engineering, Key Laboratory of Polymeric Composition and Modification, Qiqihar University, Qiqihar, China;2. Daqing Petrochemical Company, Daqing, China;3. Graduate School of Science and Technology, Niigata University, Niigata, Japan;4. School of Material Science and Engineering, Shanghai University, Shanghai, China |
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| Abstract: | Two novel chiral well‐defined rhodium complexes, Rh(cod)(L‐Phe) (cod = 1,5‐cyclooctadiene, Phe = phenylalanine) and Rh(cod)(L‐Val) (Val = valine) were synthesized, isolated by recrystallization, and characterized. The helix‐sense‐selective polymerization (HSSP) of an achiral 3,4,5‐trisubstituted phenylacetylene, p‐dodecyloxy‐m,m‐dihydroxyphenylacetylene (DoDHPA) was examined by using the two Rh complexes as catalysts. These catalysts provided high molecular weight polymers (Mw 28 × 104?45 × 104) in about 40%–85% yields. The resulting polymers exhibited a bisignated CD signal at about 300 nm and a broad signal around 470 nm, indicating that they have preferential one‐handed helical structure. The present catalysts achieved larger molar ellipticity up to θ]310 = 13.0 × 104 deg cm2/dmol than those with binary chiral catalytic systems, Rh(cod)Cl]2/(L‐phenylalaninol), Rh(cod)Cl]2/(L‐valinol), and Rh(nbd)Cl]2/(R)‐PEA. All these results manifest that the present, well‐defined Rh complexes serve as excellent catalysts for the HSSP of DoDHPA. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2346–2351 |
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| Keywords: | catalysis chiral helix‐sense‐selective polymerization L‐amino acid NMR 3 4 5‐trisubstituted phenylacetylene |
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