Performance of HPLC chiral stationary phases with two chiral units and the effect of the stereochemistry of the second chiral unit on the chiral recognition

Two chiral stationary phases (CSPs) derived from two diastereomers consisting of (R)- or (S)-alpha-naphthylethylamine and (S)-naproxen were found to show different chromatographic behaviors in resolving N-(3,5-dinitrobenzoyl)-alpha-arylalkylamines and N-(3,5-dinitrobenzoyl)-alpha- or beta-amino amides and esters. From the different chromatographic resolution behaviors on the two CSPs, the chiral recognition is proposed to be controlled mainly by the (R)- or (S)-alpha-naphthylethylamine part of the CSP. In contrast, the (S)-naproxen part of the two CSPs is proposed to exert some subordinate effects on the chiral recognition.