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) amino acid esters and amides and related analytes. The incorporation of structural features which diminish the retention of the first eluting enantiomers has led to the observation of separation factors as high as eighty for selected N-(3,5-dinitrobenzoyl)leucine amides using a normal mobile phase and as high as seven using a reversed mobile phase. The mechanistic rationale by which these chiral stationary phases were designed and the underlying reasons for the high levels of enantioselectivity are discussed.