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Calix[4]arene, calix[4]resorcarene, and cyclodextrin derivatives and their lanthanide complexes as chiral NMR shift reagents
Author(s) -
Smith Kristin J.,
Wilcox James D.,
Mirick Gudrun E.,
Wacker Lee S.,
Ryan Nicole S.,
Vensel David A.,
Readling Regina,
Domush Hilary L.,
Amonoo Edwin P.,
Shariff Sonia S.,
Wenzel Thomas J.
Publication year - 2003
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.10254
Subject(s) - chemistry , lanthanide , enantiomer , calixarene , chloroform , cyclodextrin , reagent , proton nmr , nmr spectra database , diastereomer , phenol , organic chemistry , ion , molecule , spectral line , physics , astronomy
Calix[4]arenes, calix[4]resorcarenes, and anionic cyclodextrin derivatives were examined as chiral NMR solvating agents. The calix[4]arenes were prepared by attachment of amino acids through the hydroxyl groups of the phenol rings. Chloroform‐, methanol‐, and water‐soluble derivatives were prepared and tested with a range of substrates. Chloroform‐soluble chiral calix[4]resorcarenes were prepared by attachment of chiral primary and secondary amines and examined in NMR applications with a variety of substrates. Sulfated and carboxymethylated β‐cyclodextrin are effective at causing enantiomeric discrimination in the 1 H NMR spectra of organic cations. Lanthanide ions associate at the carboxymethyl groups and cause sizeable shifts and enhancements in enantiomeric discrimination in the spectra of organic cations. The enhancements caused by the lanthanide ion are large enough that much lower concentrations of the cyclodextrin can be used as compared to conventional analyses. Chirality 15:S150–S158, 2003. © 2003 Wiley‐Liss, Inc.