Evaluation of norbornene-β-cyclodextrin-based monomers and oligomers as chiral selectors by means of nonaqueous capillary electrophoresis

Norbornen-5-yl carboxylic acid and norbornen-5-ylmethylsilyl ether-based β-cyclodextrins (β-CDs) containing up to three norbornene ester and up to five norbornene silyl ether units have been prepared from β-CD and norbornen-5-carboxylic chloride and norbornen-5-ylmethyldichlorosilane, respectively....

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Detalles Bibliográficos
Autores principales: Rozenberg, G.I., Espada, J., De Cidre, L.L., Eiján, A.M., Calvo, J.C., Bertolesi, G.E.
Formato: JOUR
Lenguaje:English
Materias:
Dansyl amino acids
Monomeric and oligomeric β-cyclodextrins
Nonaqueous capillary electrophoresis
amino acid derivative
beta cyclodextrin derivative
bicarbonate
carboxylic acid derivative
dansyl chloride
electrolyte
ester
monomer
n methylformamide
norbornene derivative
oligomer
silane derivative
aqueous solution
article
capillary electrophoresis
chirality
enantiomer
optical resolution
polymerization
beta-Cyclodextrins
Carbohydrate Sequence
Cyclodextrins
Electrophoresis, Capillary
Ethers
Molecular Sequence Data
Molecular Structure
Norbornanes
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01730835_v22_n1_p109_Rozenberg
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:Norbornen-5-yl carboxylic acid and norbornen-5-ylmethylsilyl ether-based β-cyclodextrins (β-CDs) containing up to three norbornene ester and up to five norbornene silyl ether units have been prepared from β-CD and norbornen-5-carboxylic chloride and norbornen-5-ylmethyldichlorosilane, respectively. Oligomers (n = 2-4) were prepared therefrom using ring-opening metathesis polymerization (ROMP). Monomeric and oligomeric substituted β-CDs were evaluated as chiral selectors in nonaqueous capillary zone electrophoresis using 35 mM sodium bicarbonate in N-methylformamide (NMF) as background electrolyte. Both monomeric and oligomeric norbornene ester- and norbornene silyl ether-type selectors showed good enantioresolution for dansylated (DNS-) amino acids using concentrations of the chiral selector of up to 4% w/v. A significant improvement in resolution was observed upon the introduction of up to five norbornene silyl ether units into a β-CD molecule, whereas higher degrees of substitution with norbornen-5-yl-carboxyl groups lead to a reduction in enantioresolution of DNS-amino acids. Thus, pentakis(norbornen-5-ylmethylhydroxysiloxyl)-β-CD turned out to be superior to mono(norbornen-5-ylmethylhydroxysiloxyl)-β-CD in terms of enantioresolution. Moreover, norbornene silyl ether-type selectors were found to be more efficient than norbornene ester-type selectors. Finally, oligomeric selectors were found to possess superior or at least comparable enantioselectivity in the separation of DNS-amino acids compared to the parent monomers. A maximum in enantioresolution was obtained with oligo(pentakis(norbornen-5-ylmethylhydroxysiloxyl)β-CD).

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