SYNTHESIS AND MECHANISTIC STUDY OF NOVEL PI-BASIC CHIRAL STATIONARY PHASES DERIVED FROM TYROSINE

This work was a study of novel pi-basic, chiral stationary phases (CSPs) deriving from tyrosine and bearing two stereogenic centres. These CSPs differ in the nature of the amidic substituent (n-butyl or tert-butyl) and by the configuration of both the chiral centres (S or R). The enantioselectivity and elution order of various 3, 5-dinitrobenzoyl derivatives were studied using liquid and supercritical fluid chromatographic modes. The chromatographic data allowed determination of the influence of the CSP structure (also studied according to factorial designs) and determination of the influence of the solute structure. Chiral recognition mechanisms which are in good agreement with these observations are proposed. Finally, this paper reports the enantiomeric resolution of two compounds of pharmaceutical interest (warfarin and ICI 176334).