IMPACT OF SUBSTITUENTS ON THE ENANTIOSEPARATION OF RACEMIC 2-AMIDOTETRALINS ON POLYSACCHARIDE STATIONARY PHASES .1. CHIRALCEL OD

The direct enantiomeric separation of 32 racemic 2-amidotetralins on t he commercially available tris-(3,5-dimethylphenylcarbamate) derivativ e of cellulose, coated on silica gel (Chiralcel OD), is presented. To date, the selection of a column for the chiral separation of a racemic mixture is done empirically. Studying the impact of small changes in the chemical structure of a series of amidotetralins on the separation behavior may help to give an insight in the chiral recognition mechan ism. The amidotetralins differed structurally in three of their substi tuents, which were never directly located on the chiral carbon atom. T he enantiomers of 24 out of 32 amidotetralins could be resolved with a resolution >1.5. Hydrogen bonding and pi-pi interactions are supposed to be the major analyte-chiral stationary phase (CSP) interactions. H owever, the spatial arrangement of the enantiomers may play an importa nt role too. Increasing the bulkiness of the acyl substituent led to a n increase in the resolution (R(s)), whereas a more bulky substituent on the aromatic ring resulted in a very low resolution. The introducti on of a chlorine atom into the acyl substituent additionally increased the resolving power. (C) 1997 Wiley-Liss, Inc.