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This book reviews chiral polymer synthesis and its application to asymmetric catalysis.It features the design and use of polymer-immobilized catalysts and methods for their design and synthesis.Chapters cover peptide-catalyzed and enantioselective synthesis, optically-active polymers, and continuous flow processes.

Under the acyclic diene metathesis (ADMET) reaction condition, the C3-vinyl groups of cinchona alkaloids readily react with each other to form a C-C bond. A novel type of cinchona alkaloid polymers was synthesized from dimeric cinchona squaramides using the Hoveyda-Grubbs’ second-generation catalysts (HG2) by means of ADMET reaction. The chiral polymers, containing cinchona squaramide moieties in their main chains, were subsequently employed as catalysts for the enantioselective Michael reaction to give the corresponding chiral adducts in high yields with excellent enantioselectivity and diastereoselectivity. Both enantiomers from the asymmetric Michael reaction were distinctively prepared while using the polymeric catalysts, possessing pseudoenantiomeric structures. The catalysts were readily recovered from the reaction mixture and recycled several times due to the insolubility of the cinchona-based squaramide polymers.

Main-chain chiral quaternary ammonium polymers were successfully synthesized by the quaternization polymerization of cinchonidine dimer with dihalides. The polymerization occurred smoothly under optimized conditions to give novel type of main-chain chiral quaternary ammonium polymers. The catalytic activity of the polymeric chiral organocatalysts was investigated on the asymmetric benzylation of N-(diphenylmethylidene)glycine tert-butyl ester.

This chapter contains sections titled: Introduction Polymeric Chiral Catalyst Synthesis of Optically Active Polymers References

A poly(vinylphenol)-block-polystyrene diblock copolymer (PVPh-b-PSt) forms micelles in the presence of 1,4-butanediamine (BDA) in 1,4-dioxane, a nonselective solvent. The micellization proceeds through the formation of hydrogen bond cross-linking between the PVPh blocks via BDA, and the dissociation and reconstruction of the micelles is reversibly controlled by temperature. We explored the thermodynamics and kinetics on the micellization of the nonamphiphilic PVPh-b-PSt copolymer by BDA. Light scattering studies demonstrated that an equilibrium existed between the micelles and the unimers. The equilibrium constants were determined for the dissociation and the reconstruction of the micelles on the basis of variation in the aggregation number of the micelles. The equilibrium constant of the dissociation showed a good agreement with the reciprocal of the equilibrium constant of the reconstruction. Based on the equilibrium constants, the standard Gibbs energy, enthalpy, and entropy of the dissociation and reconstruction were estimated. The standard enthalpy was [delta] H° = 30-40 kJ mol^sup -1^ for the dissociation. The enthalpy of the reconstruction was obtained as a negative value, however, there was a negligible difference in the absolute values of [delta] H° between the dissociation and the reconstruction. The rate constant of the micellization was ca. 10^sup 2^ times larger than the back reaction, and increased with a decrease in the temperature.[PUBLICATION ABSTRACT]

A poly(vinylphenol)-block-polystyrene diblock copolymer (PVPh-b-PSt) forms micelles in the presence of 1,4-butanediamine (BDA) in 1,4-dioxane, a nonselective solvent. The micellization proceeds through the formation of hydrogen bond cross-linking between the PVPh blocks via BDA, and the dissociation and reconstruction of the micelles is reversibly controlled by temperature. We explored the thermodynamics and kinetics on the micellization of the nonamphiphilic PVPh-b-PSt copolymer by BDA. Light scattering studies demonstrated that an equilibrium existed between the micelles and the unimers. The equilibrium constants were determined for the dissociation and the reconstruction of the micelles on the basis of variation in the aggregation number of the micelles. The equilibrium constant of the dissociation showed a good agreement with the reciprocal of the equilibrium constant of the reconstruction. Based on the equilibrium constants, the standard Gibbs energy, enthalpy, and entropy of the dissociation and reconstruction were estimated. The standard enthalpy was Delta *D H? = 30--40 kJ mol-1 for the dissociation. The enthalpy of the reconstruction was obtained as a negative value, however, there was a negligible difference in the absolute values of Delta *D H? between the dissociation and the reconstruction. The rate constant of the micellization was ca. 102 times larger than the back reaction, and increased with a decrease in the temperature.

SummaryMukaiyama aldol reaction smoothly occurred between bis(triethylsilyl enol ether) and dialdehyde in the presence of Lewis acid catalyst to yield polymers that consist of β-hydroxy carbonyl repeating units. When chirally modified Lewis acid catalyst was used, the optically active poly(β-hydroxy ketone)s were obtained by means of the asymmetric aldol polymerization.