Structural Modifications of Cinchonan-Type Selectors

It is system-intrinsic for highly selective chiral recognition events that the enantiore-cognition capability of a chemical receptor or selector system is somehow restricted to a certain group of target selectands. While universal applicability of a CSP may certainly be a desired, frequently postulated property for a powerful chiral phase, it is for sure that it eventually remains a wish because of the contradictive and mutually exclusive nature of specificity and universal applicability. To get around 

FIGURE 1.8 Effect of the mole fraction of polar modifier (ethyl acetate) in n-hexane on the reciprocal of the retention factor for the separation of 3-chloro-l-phenylpropanol enantiomers on a 0-9-(terf-butylcarbamoyl)quinidine CSP. Temperature, 22°C. (Reproduced from L. Asnin, and G. Guiochon, J. Chromatogr. A, 1091 11 (2005). With permission.) 

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