Use of derivatized cyclodextrins as chiral selectors for the separation of enantiomers by gas chromatography

摘要: Summary The state-of-the-art of enantioseparations various chiral compounds on derivatized cyclodextrins, employed as stationary phases (CSPs) by gas chromatography, is reviewed. Heptakis(2,3,6- O -trimethyl)-β-cyclodextrin and octakis(3- -butanoyl-2,6-di- -pentyl)-γ-cyclodextrin (Lipodex E), either dissolved in a semipolar polysiloxane or bonded to poly(dimethylsiloxane) (Chirasil-Dex), proved be the most popular selectors. Special applications refer use heptakis (2,3-di- -acetyl-6- - tert -butyldimethylsilyl)-β-cyclodextrin heptakis(2,3-di- -methyl-6- -butyldimethylsilyl)-β-cyclodextrin. Enantioselectivity generally low with enantioseparation factors range 1.02  α D,L (Δ G ) =  RT ln( ) only 0.014–0.14 kcal/mol at 100 °C. Therefore, reliable mechanistic studies chirality recognition are still absent. Concise thermodynamic parameters have been measured selected systems which involve large enantioselectivies 1.5