Chiral recognition in NMR spectroscopy using crown ethers and their ytterbium(III) complexes

Thomas J. Wenzel*, Bailey E. Freeman, David C. Sek, Jason J. Zopf, Takashi Nakamura, Jin Yongzhu, Keiji Hirose, Yoshito Tobe

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

44 Scopus citations

Abstract

Chiral crown ethers 1 and 5 are useful enantiomeric discriminating agents in 1 H NMR spectroscopy for neutral and protonated primary amines, amino acids, and amino alcohols. The presence of the carboxylic acid groups in 1 and 5 provide sites at which ytterbium(III) can bind. Adding ytterbium(III) nitrate to crown-substrate mixtures in methanol-d 4 causes shifts in the spectra of substrates and often enhances the chiral discrimination in the 1 H NMR spectrum. The enhancement in enantiomeric discrimination that occurs in the presence of ytterbium(III) allows lower concentrations of the crown ether to be used in chiral recognition studies. Several amide derivatives of 1 were prepared and evaluated as chiral NMR discriminating agents, although except for 1e, these were less effective than 1.

Original languageEnglish
Pages (from-to)1536-1547
Number of pages12
JournalAnalytical and Bioanalytical Chemistry
Volume378
Issue number6
DOIs
StatePublished - 1 Mar 2004

Keywords

  • Chiral recognition
  • Crown ether
  • Enantiomeric discrimination
  • Lanthanide
  • NMR spectroscopy

Fingerprint Dive into the research topics of 'Chiral recognition in NMR spectroscopy using crown ethers and their ytterbium(III) complexes'. Together they form a unique fingerprint.

Cite this