Optically active copolymers of pairs of three monomers, triphenyl (methyl methacrylate)and one or two pyridyl substituted methyl methacrylate homologues, were obtained by helix-sense-selective copolymerization using c...Optically active copolymers of pairs of three monomers, triphenyl (methyl methacrylate)and one or two pyridyl substituted methyl methacrylate homologues, were obtained by helix-sense-selective copolymerization using complexes of organolithium with chiral ligand as anionicinitiators in toluene at low temperature. The copolymers obtained with (-)-sparteine (Sp) and(S,S)-(+)-and (R, R)-(-)-2, 3-dimethoxy-1, 4-bis (dimethylamino) butanes((+)-and (-)-DDB) complexes of organolithium showed low optical activity, but PMP complex with N, N-diphenylethyleneamine monolithium amide (PMP-DPEDA-Li) was effective in synthesizingcopolymers of high optical rotation ([α]_D^(25) about+320～1370°)which were comparable to thoseof relative homopolymers with one-handed helical structure.展开更多
（S）-2-aminobutyric acid being initial raw material,（S）-2-hydroxybutyric acid methyl ester was synthesized by means of a three step reaction of hydroxylation, salification and esterification. The product had a yiel...（S）-2-aminobutyric acid being initial raw material,（S）-2-hydroxybutyric acid methyl ester was synthesized by means of a three step reaction of hydroxylation, salification and esterification. The product had a yield rate of 60.4%, purity of 99% and ee value higher than 99% by characterization of GC, HPLC and 1H NMR. This synthesis technique has advantages of high purity and ee value, low cost, short reaction time and mild reaction conditions so that it is suitable for production on industrial scale.展开更多
基金This project is supported by the National Natural Science Foundation of China and the President Foundation of Academia Sinica
文摘Optically active copolymers of pairs of three monomers, triphenyl (methyl methacrylate)and one or two pyridyl substituted methyl methacrylate homologues, were obtained by helix-sense-selective copolymerization using complexes of organolithium with chiral ligand as anionicinitiators in toluene at low temperature. The copolymers obtained with (-)-sparteine (Sp) and(S,S)-(+)-and (R, R)-(-)-2, 3-dimethoxy-1, 4-bis (dimethylamino) butanes((+)-and (-)-DDB) complexes of organolithium showed low optical activity, but PMP complex with N, N-diphenylethyleneamine monolithium amide (PMP-DPEDA-Li) was effective in synthesizingcopolymers of high optical rotation ([α]_D^(25) about+320～1370°)which were comparable to thoseof relative homopolymers with one-handed helical structure.
文摘（S）-2-aminobutyric acid being initial raw material,（S）-2-hydroxybutyric acid methyl ester was synthesized by means of a three step reaction of hydroxylation, salification and esterification. The product had a yield rate of 60.4%, purity of 99% and ee value higher than 99% by characterization of GC, HPLC and 1H NMR. This synthesis technique has advantages of high purity and ee value, low cost, short reaction time and mild reaction conditions so that it is suitable for production on industrial scale.
