A mixed stationary phase containing two versatile cyclodextrin-based selectors for the simultaneous gas chromatographic enantioseparation of racemic alkanes and racemic α-amino acid derivatives☆

Gas chromatographic enantioseparation of derivatized α-amino acids on chiral stationary phases—Past and present

“…Whereas permethylated Chirasil-␥-Dex provided only few baseline enantioseparations, permethylated Chirasil-␣-Dex and Chirasil-␤-Dex 5 exhibited complementary behaviour which may indicate the need of employing the two selectors in one CSP as proposed previously [36]. By mixing the two versatile CD selectors octakis ( [83] and heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-␤-cyclodextrin in the polysiloxane PS 086, a comprehensive enantioselectivity spectrum for racemic unfunctionalized alkanes, racemic derivatized ␣-amino acids, lactones, diols, secondary alcohols, ketones and terpenes has been achieved [84].…”

Separation of Enantiomers by Gas Chromatography on Chiral Stationary Phases

“…Subsequently, in a number of papers the use of mixed binary CD selector systems for the enantioseparation of different classes of chiral compounds has been described [79,[100][101][102][103][104][105]. Recently, a comprehensive enantioselectivity spectrum toward racemic unfunctionalized alkanes and racemic derivatized α-amino acids as well as to other classes of racemic compounds, such as lactones, diols, secondary alcohols, ketones, and terpenes, has been realized by diluting the two versatile CD selectors octakis(6-O-methyl-2,3-di-O-pentyl)-γ-cyclodextrin (Lipodex G) [81] and heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin [87] in the polysiloxane PS-086 [106].…”

Aqueous biphasic hydroformylation in the presence of cyclodextrins mixtures: evidence of a positive synergistic effect

“…Enhancement of aqueous solubility of a poorly water-soluble cyclic undecapeptide 7 and a potent glucocorticoid steroid 8 using respectively α-CD/HP-β-CD mixtures and α-CD/HP-γ-CD mixtures is along the same lines. Such synergistic effects between different CDs have also been highlighted when mixed GC stationary phases consisting of two different CD derivatives were used in resolving enantiomers [9][10][11][12] or in positional isomers compounds separation. 13,14 In the field of aqueous organometallic catalysis, CDs are mainly used as mass transfer promoters between aqueous and organic layers by forming inclusion complexes with the substrate.…”