Chromatographic resolution and elution order of alkyl aryl and aryl benzyl sulfoxides on cellulose-based chiral stationary phases

Abstract

Several alkyl aryl and aryl benzyl sulfoxides have been prepared in optically active form via enantioselective Ti-catalyzed oxidation of the corresponding sulfides. The absolute configuration was assigned on the basis of optical rotation while in the case of some new sulfoxides it was determined by the analysis of their circular dichroism spectra. The alkyl aryl sulfoxides have been efficiently resolved by CHIRALCEL OB chiral stationary phase (CSP) while the aryl benzyl sulfoxides were better separated on CHIRALCEL OJ CSP. In both cases the S enantiomer was always eluted first. This finding can then allow to determine the absolute configuration of alkyl aryl and aryl benzyl sulfoxides on the basis of their elution order on these CSPs.