CHIRAL STATIONARY-PHASE DESIGN - USE OF INTERCALATIVE EFFECTS TO ENHANCE ENANTIOSELECTIVITY

Two new chiral stationary phases derived from L-proline were designed specifically to separate the enantiomers of N-(3,5-dinitrobenzoyl) ami no acid esters and amides and related analytes. The incorporation of s tructural features which diminish the retention of the first eluting e nantiomers has led to the observation of separation factors as high as eighty for selected N-(3,5-dinitrobenzoyl)leucine amides using a norm al mobile phase and as high as seven using a reversed mobile phase. Th e mechanistic rationale by which these chiral stationary phases were d esigned and the underlying reasons for the high levels of enantioselec tivity are discussed.