Optical activity chiral recognition ability

Optically Active Polymers with Chiral Recognition Ability... 

OPTICALLY ACTIVE POLYMERS WITH CHIRAL RECOGNITION ABILITY... 

Among optically active polymers, polysaccharide derivatives are particularly valuable. Polysaccharides such as cellulose and amylose are the most readily available optically active polymers and have stereoregular sequences. Although the chiral recognition abilities of native polysaccharides are not remarkable, they can be readily converted to the esters and carbamates with high chiral recognition abilities. The chiral recognition mechanism of these derivatives has been clarified to some extent. 

Oare, D. A., Stereochemistry of the Base-Promoted Michael Addition Reaction, 19, 227 Acyclic Stereocontrol in Michael Addition Reactions of Enamines and Enol Ethers, 20, 87 Okamoto, Yoshio, Optically Active Polymers with Chiral Recognition Ability, 24, 157. 

Anionic Catalysis Several bulky methacrylates afford highly isotactic, optically active polymers having a single-handed helical structure by asymmetric polymerization. The effective polymerization mechanism is mainly anionic but free-radical catalysis can also lead to helix-sense-selective polymerization. The anionic initiator systems can also be applied for the polymerization of bulky acrylates and acrylamides. The one-handed helical polymethacrylates show an excellent chiral recognition ability when used as a chiral stationary phase for high-performance liquid chromatography (HPLC) [97,98]. 

Figure 1(b) shows what kinds of CSPs has been used in HPLC for analyzing chiral compounds. There are two types of CSPs one is prepared from small molecules with a chiral recognition ability and the other from optically active polymers. It is clear that the... 

Okamoto, Y. Yashima, E. and Yamamoto, C. (2003) Optically active polymers with chiral recognition ability, in Green, M.M., Nolte, R.J.M., and Meijer, E.W. (eds.), Materials Chirality Volume 24 of Topics in Stereochemistry, John Wiley Sons Inc., New Jersey, pp. 157-208. 

Okamoto, Y., Mohri, H., Ishikura, M., Hatada, K., and Yuki, H., Optically active poly(diphenyl-2-pyridylmethyl methacrylate) asymmetric synthesis, stability of helix, and chiral recognition ability, J. Polymer Sci. Polymer Symp., 74, 125, 1986. 

The optically active polymers obtained from D3PyMA, PB2PyMA, 2PyDBSMA, and 3PyDBSMA show chiral recognition ability toward some racemic compounds in chiral HPLC or chiral adsorption experiments, though the ability was generally lower than that of poly(TrMA).16 59-62... 

Optically active poly-55 shows chiral recognition ability toward several racemates including Co-(acac)3.138... 

A polyaniline film prepared by doping an emeral-dine base with optically active CSA showed a CD spectrum. Even after dedoping, the film exhibited CD bands which were different in pattern from those of the original dedoped film, suggesting that a chiral conformation such as a helix remains in the polymer chain. The dedoped film exhibited chiral recognition ability toward phenylalanine.235... 

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