NMR spectroscopic investigations involving extensive use of ROESY and DOSY techniques and comparison with silylated-acetylated linear dextrins as acyclic model compounds shed light on the origin of the phenomenon of enantiodiscrimination of fluorinated α-amino acid derivatives by heptakis[2,3-di-O-acetyl-6-O-(tert-butyldimethylsilyl)]-β- cyclodextrin. The effectiveness and versatility of the cyclic derivatized oligosaccharide as a chiral solvating agent for the NMR determination of enantiomeric purity in the same class of compounds is demonstrated. A regular correlation between the relative positions of enantiomers’ signals and absolute configurations is observed.
External vs. internal interactions in the enantiodiscrimination of fluorinated alpha-amino acid derivatives by heptakis[(2,3-di-O-acetyl-6-O-(tert-butyldimethylsilyl)]-beta-cyclodextrin, a powerful chiral solvating agent for NMR spectroscopy
UCCELLO BARRETTA, GLORIA;BALZANO, FEDERICA;
2008-01-01
Abstract
NMR spectroscopic investigations involving extensive use of ROESY and DOSY techniques and comparison with silylated-acetylated linear dextrins as acyclic model compounds shed light on the origin of the phenomenon of enantiodiscrimination of fluorinated α-amino acid derivatives by heptakis[2,3-di-O-acetyl-6-O-(tert-butyldimethylsilyl)]-β- cyclodextrin. The effectiveness and versatility of the cyclic derivatized oligosaccharide as a chiral solvating agent for the NMR determination of enantiomeric purity in the same class of compounds is demonstrated. A regular correlation between the relative positions of enantiomers’ signals and absolute configurations is observed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.