Intermolecular (1)H-(1)H Two-Dimensional Nuclear Overhauser Enhancements in the Characterization of a Rationally Designed Chiral Recognition System.

Chiral stationary phases (CSPs) for liquid chromatography derived from N-(acyl)proline-3,5-dimethylanilides separate the enantiomers of N-(3,5-dinitrobenzoyl)-alpha-amino esters and amides with high levels of selectivity. These CSPs have been used to assemble a large body of chromatographic data which indirectly supports the validity of the mechanistic rationale originally used in the design of these CSPs. We herein report (1)H and (13)C chemical shift data obtained when the (S)-enantiomer of chiral solvating agent (CSA) 3, a soluble analogue of the selector used in CSP (S)-1, acts on each of the enantiomers of the dimethylamide of N-(3,5-dinitrobenzoyl)leucine, 2.