Chiral separation of primary amino compounds using a non-chiral crown ether with beta-cyclodextrin by capillary electrophoresis.
A non-chiral crown ether (18-crown-6) along with beta-cyclodextrin (beta-CD) was used to achieve enantioselective separations of primary amino compounds in capillary electrophoresis. In this new method, the amino group of these compounds is protonated in a low pH separation buffer and forms a selective host-guest complex with the crown ether (amino compound+18-crown-6). The hydrophobic portion of the host-guest complex is then incorporated into the cavity of the beta-cyclodextrin. The amino compound is sandwiched between the crown ether and the cyclodextrin (18-crown-6+amino compound+beta-CD) and thus determines or enhances the enantioselective recognition. It is postulated that the formation of this sandwich results in a more selective chiral interaction between the molecule and beta-cyclodextrin. The chiral recognition is dependent upon the formation of this sandwich complex. This method has been used to achieve enantioselectivity of primary amino compounds with a wide variety of substitutions.
Huang
W X
WX
Sandoz Research Institute, East Hanover, NJ 07936, USA.
Xu
H
H
Fazio
S D
SD
Vivilecchia
R V
RV
D000588:Amines / Q000032:analysis*; D000596:Amino Acids / Q000032:analysis*; D000605:Amino Alcohols / Q000032:analysis*; D043844:Crown Ethers; D003505:Cyclodextrins; D019075:Electrophoresis, Capillary; D004988:Ethers, Cyclic; D013237:Stereoisomerism; D047392:beta-Cyclodextrins
D000588:Amines; D000596:Amino Acids; D000605:Amino Alcohols; D043844:Crown Ethers; D003505:Cyclodextrins; D004988:Ethers, Cyclic; D047392:beta-Cyclodextrins; C038119:heptakis(2,6-O-dimethyl)beta-cyclodextrin; C015762:18-crown-6