Polymer chirally imprinted

There exists the possibility that one can imprint a chiral arrangement on a catalytic surface. Although chiral imprinting is now occurring on silica surfaces14 and in polymers,15 it has not been used to induce chirality in metal surfaces. This is difficult to explore. 

Different classifications for the chiral CSPs have been described. They are based on the chemical structure of the chiral selectors and on the chiral recognition mechanism involved. In this chapter we will use a classification based mainly on the chemical structure of the selectors. The selectors are classified in three groups (i) CSPs with low-molecular-weight selectors, such as Pirkle type CSPs, ionic and ligand exchange CSPs, (ii) CSPs with macrocyclic selectors, such as CDs, crown-ethers and macrocyclic antibiotics, and (iii) CSPs with macromolecular selectors, such as polysaccharides, synthetic polymers, molecular imprinted polymers and proteins. These different types of CSPs, frequently used for the analysis of chiral pharmaceuticals, are discussed in more detail later. 

The imprinting of polymer supports is an exciting development in the immobilization of transition metal complexes. The process involves the copolymerization of an inorganic or an organic template into a crosslinked polymer network. In a subsequent step, the template is chemically removed leaving an imprint of molecular dimensions in the resin. Ideally, the imprint retains chemical information related to the size and shape of the template. This approach has been used to prepare chiral imprints in otherwise achiral polymer networks. The method is outlined in Scheme... 

Keywords. 3-Functionalized ketones, a-Keto acid derivatives. Cinchona modified Pt catalysts. Chiral imprints. Chiral metal surfaces. Chiral polymers. Cyanohydrin formation. Cyclic Dipeptides, Epoxidation catalysts. Heterogeneous catalysts. Hydrogenation catalysts. Modified metal oxides. Polypeptides, Tartrate-modified Nickel catalysts... 

Chiral imprints. The imprinting of organic [50] and inorganic materials [51] with transition state analog templates should, at least in principle, lead to what could be called artificial catalytic antibodies. Up to now, either the chiral recognition and/or the catalytic properties of such materials are still very poor. Some examples are a zeolite p, partially enriched in polymorph A [51], chiral footprints on silica surfaces [52], or several imprinted polymers [50]. 

Allender CJ, Brain KR, Heard CM (1997) Binding cross-reactivity of Boc-phenyl-alanine enantiomers on molecularly imprinted polymers. Chirality 9(3) 233-237... 

Gomez-caballero, A., Guerreiro, A., Karim, K., Piletsky, S., Goicolea, M. A., Barrio, R. J. (2011). Chiral imprinted polymers as enantiospecific coatings of stir bar sorptive extraction devices,... 

Allender, C.J. Brain, K.R. Heard, C.M. Binding cross-reactivity d Boc-phenylalanine enantiomers on molecularly imprinted polymers. Chirality 1997, 9, 233-237. 

Chiral stationary phases that are currently available can be classified into those containing cavities (cellulose derivatives, cyclodextrins, synthetic polymers, crown ethers, and chiral imprinted gels), affinity phases (bovine serum albumin, human serum albumin, a-glycoprotein, enzymes), multiple hydrogen-bond phases, Ti-donor and Ti-acceptor phases, and chiral ligand exchange phases. This classification scheme was used in a review that gave numerous pharmaceutical examples of separation by... 

This technique is based on the preparation of synthetic polymers with specific selectivity by using chiral imprinting molecules mixed with functional and cross-linking monomers (usually methacrylic acid and ethylene glycol dimethacrylate, respectively), capable of interacting with such molecules. 

Chiral synthetic polymer phases can be classified into three types. In one type, a polymer matrix is formed in the presence of an optically pure compound to moleculady imprint the polymer matrix (Fig. 10) (107,108). Subsequent to the polymerisation, the chiral template is removed, leaving the polymer matrix... 

Sellergren, B. and Shea, K. J., Chiral ion-exchange chromatography Correlation between solute retention and a theoretical ion-exchange model using imprinted polymers, /. Chromatogr. A, 654, 17, 1993. 

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