Experimental support differenciating two proposed chiral recognition models for the resolution of N-(3,5-Dinitrobenzoyl)-α-arylalkylamines on high-performance liquid chromatography chiral stationary phases

In rationalizing the odd chromatographic behavior for the separation of the enantiomers of N-(3,5-dinitrobenzoyl)-α-arylalkylamines on HPLC chiral stationary phases (CSPs) derived from α-(6,7-dimethyl-1-naphthyl)alkylamines, we initially suggested the occurrence of two competing, opposite sense chiral recognition processes termed the “dipole-stacking process” and the “hydrogen-bonding process”. A simplified “single mechanism” model was later suggested with the importance of face to edge π–π interaction between aromatic rings come to recognized. The initial and subsequent chiral recognition models can be differentiated by noting the chromatographic trends for the enantioseparation of a homologous series of N-(3,5-dinitrobenzoyl)-α-(p-alkylphenyl)ethylamines on the aforementioned CSPs. Data so obtained were consistent with the second “single mechanism” model but not with the first “two competing mechanism” model. From these results, it has been concluded that the “single mechanism” model is more plausible than the “two competing mechanism” model.