A Chiral Stationary Phase Derived from (R,R)-Tartramide with Broadened Scope of Application to the Liquid Chromatographic Resolution of Enantiomers

Article abstract of DOI:10.1021/jo00388a026

An understanding of the retention process of solute enantiomers on a chiral stationary phase (CSP) would indicate the importance of eliminating the nonenantioselective, i.e., solute-silanol, interaction that occurs in this process.For clarification of this matter, a CSP in which a (R,R)-N,N'-dialkyltartramide derivative is linked to the silica gel surface via 11 methylene units and the remaining silanol groups are trimethylsilylated was synthesized.This CSP was found capable of chiral recognition of broad categories of enantiomers containing α- or β-hydroxycarbonyl, α-amino acid, β-aminoalcohol, primary amine derivatives, barbiturates, glutarimide, α-hydroxy ketoximes, carbinols, 1,2-diols, and bi-β-naphthol.The driving force to bring about enantioselective association is ascribable to hydrogen bonding.The effects of a reduction in the number of remaining silanol groups on CSP and a long alkyl chain as a linkage of the tetramide moiety to CSP are discussed on the basis of retentivity of enantiomers.