Enantiomeric separations of binaphthyl derivatives by capillary electrophoresis using N‐(2‐hydroxydodecyl)‐L‐threonine as chiral selector: Effect of organic additives

Abstract

The chiral selectivity of a novel amphiphile, N-(2-hydroxydodecyl)-L-threonine (2-HDT), was evaluated for enantiomeric resolution of three binaphthyl derivatives (+/-)-1,1'-bi-2-naphthol, (+/-)-1,1'-binaphthyl-2,2'-diamine, and (+/-)-1,1'-binaphthyl-2,2'-diylhdrogen phosphate (BNP) by micellar EKC. The effects of three organic modifiers, methanol, isopropanol, and acetonitrile, on the separations of enantiomers of these compounds were investigated. Separation of enantiomers could be achieved in relatively dilute solutions of the pure surfactant. However, best separations of enantiomers were obtained only in the presence of 10% v/v acetonitrile. Enantiomeric impurity in nonracemic mixtures of R- and S-forms of BNP was determined.

Recent advances of enantioseparations in capillary electrophoresis and capillary electrochromatography

“…Furthermore, this group synthesized a long alkyl-chain amino acid derivative, sodium N-(2-hydroxydodecyl)-L-threonine, whose critical micelle concentration was as low as 0.55 mmol L À1 . 89 Tano et al 90 synthesized four new anionic hydrophilic chiral surfactants containing sugar moieties, and utilized them in the enantioseparation of dansyl amino acids.…”

Improved simultaneous enantioseparation of β‐agonists in CE using β‐CD and ionic liquids

“…Sometimes they were effective, although enantiomers still could not be completely enantioseparated using them only. Under these circumstances, non‐chiral reagents, including organic solvents 18, 19, surfactants 20 and microemulsions 21, were added to assist the chiral selector to improve enantioseparations. Generally, surfactants have long hydrophobic chains, which could penetrate into the hydrophobic cavity of chiral selectors, resulting in poor resolutions.…”

Chiral Separations: Fundamental Review 2010

“…Micelles. A novel amphiphile, N-(2-hydroxydocecyl)-L-threonine was used in the enantiomeric separations of binaphthyl derivatives by micellar EKC (194). Dodecyl thioglycoside surfactants were used in MEKC for the enantiomeric separation of dansylated amino acids (195).…”

“…A novel amphiphile, N -(2-hydroxydocecyl)- l -threonine was used in the enantiomeric separations of binaphthyl derivatives by micellar EKC . Dodecyl thioglycoside surfactants were used in MEKC for the enantiomeric separation of dansylated amino acids .…”