Axially dissymmetric bianthracene-based chiral stationary phase for the high-performance liquid chromatographic separation of enantiomers

Enantiomerically pure (aR)-1,1′-bianthracene-2,2′-dicarboxylic acid is prepared and bonded to a 3-aminopropylsilanized silica via an amide linkage to afford a novel chiral stationary phase (CSP 2) for high-performance liquid chromatographic separation of enantiomers. The performance of CSP 2 is compared with that of the previously prepared binaphthalene-based CSP (CSP 1), which was obtained by bonding axially dissymmetric (aS)-1,1′-binaphthalene-2,2′-dicarboxylic acid to the silica. As is expected from the chiral discrimination mechanism proposed for CSP 1, in which simultaneous π-donor-acceptor interaction and dipole-stacking interaction between the CSP and the analytes play a critical role for the separation of enantiomers, CSP 2 shows a greatly improved performance as compared with CSP 1 in the separation of a wide range of enantiomeric amino acids, amines, alcohols and carboxylic acids as the 3,5-dinitrophenyl derivatives.