most probably a random structure by CD studies. It was found by titration spectrum that an inclusion complex of 1:1 ratio (association constant; azobenzene (guest, Ka=1.0 x 10(4)M-1) is formed between 1,12-dodecano-bis(L.-Phe-L-Phe-L-Leu) and [L0]=1.758 x 10(-5)M-1). Moreover, the stability of the complexes was increased in order of 1,12-dodecano-bis(L-Phe-L-Phe-L-Leu) x azobenzene> 1,12-dodecano-bis(L-Phe-L-Phe-L-Val)
Chiral bis(amino amides) as chiral solvating agents for enantiomeric excess determination of α-hydroxy and arylpropionic acids
作者:Belén Altava、M. Isabel Burguete、Noèlia Carbó、Jorge Escorihuela、Santiago V. Luis
DOI:10.1016/j.tetasy.2010.05.010
日期:2010.4
A family of bis(amino amides) derived from natural amino acids has been synthesized and tested for the NMR enantiodiscrimination, as chiral solvating agents, for enantiomeric excess determination of some carboxylic acids. Those bis(amino amide) receptors contain different structural modifications and the splitting of the signals of the acids, after addition of the corresponding CSAs, depends on those structural variables. The influence of aminoacid side chain and the nature of the aliphatic spacer are important parameters to obtain good chiral discriminations. The results obtained clearly show the chiral recognition abilities of these bis(amino amide) ligands and suggest their advantageous use as chiral solvating agents for carboxylic acids. The binding between bis(amino amides) and carboxylic acids has been studied by ESI-MS, NMR, DSC, and molecular modeling. The data suggest that enantiodiscrimination involves the formation of an ionic pair after proton transfer from the carboxylic substrate to the bis(amino amides). (C) 2010 Elsevier Ltd. All rights reserved.
Schroeder,E. et al., Justus Liebigs Annalen der Chemie, 1961, vol. 646, p. 101 - 118
作者:Schroeder,E. et al.
DOI:——
日期:——
Self-Assembly of Small Peptidomimetic Cyclophanes
作者:Jorge Becerril、M. Isabel Burguete、Beatriu Escuder、Francisco Galindo、Raquel Gavara、Juan F. Miravet、Santiago V. Luis、Gabriel Peris
DOI:10.1002/chem.200400031
日期:2004.8.20
The self-assembly of a series of smallpeptidomimeticcyclophanes in organic solvents was studied. X-ray diffraction, NMR spectroscopy, and molecular modelling were used to understand the structural features of these self-assembling compounds both at the molecular and supramolecular level. The factors that could influence the formation of gels rather than crystals were studied and a model for the arrangement