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DOI: 10.1039/A705921C (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 2, 1998, 19-24

Enantiomer discrimination using lipophilic cyclodextrins studied by electrode response, pulsed-gradient spin-echo (PGSE) NMR and relaxation rate measurements

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Ayelet Gafni, Yoram Cohen, Ritu Kataky, Simon Palmer and David Parker

Abstract

The diastereoisomeric complexes formed between 2,6-di-O-alkyl-α- and β-cyclodextrins and the arylammonium ions propranolol, ephedrine and amphetamine have been studied by electrode response and NMR methods. Enantioselectivity in binding propranolol is 3.3∶1 with 2,6-di-O-dodecyl-β-cyclodextrin in favour of the (+)-enantiomer as revealed by measurement of the association constant using pulsed-gradient spin-echo (PGSE) NMR methods. In all of the cases of enantiodifferentiation studied here, the (+)-enantiomer is more strongly bound by the cyclodextrin. Relaxation rate measurements of the host and guest proton NMR resonances highlight the importance of hydrogen-bonding in enantiomer discrimination.

References

  1. P. S. Bates, R. Kataky and D. Parker, Analyst, 1992, 117, 1313 RSC.
  2. (a) P. S. Bates, A. F. Patti and D. Parker, J. Chem. Soc., Perkin Trans. 2, 1994, 657 RSC; (b) P. S. Bates, R. Kataky and D. Parker, J. Chem. Soc., Perkin Trans. 2, 1994, 669 RSC.
  3. P. M. Kelly, R. Kataky, D. Parker and A. F. Patti, J. Chem. Soc., Perkin Trans. 2, 1995, 1955 RSC.
  4. R. Kataky, P. S. Bates and D. Parker, Analyst, 1994, 119, 181 RSC.
  5. R. Kataky, S. Palmer and D. Parker, Electroanalysis, 1997, in the press Search PubMed.
  6. R. Kataky and D. Parker, Analyst, 1996, 121, 1829 RSC; R. Kataky and D. Parker, Chem. Commun., 1997, 141 RSC.
  7. (a) D. W. Armstrong, T. J. Ward, R. D. Armstrong and T. E. Beesley, Science, 1986, 232, 1132 CAS; (b) D. W. Armstrong, T. J. Ward, A. Czech, B. P. Czech and R. A. Bartsch, J. Org. Chem., 1985, 50, 5556 CrossRef CAS; (c) D. W. Armstrong, S. Chen, C. Chang and S. Chang, J. Liq. Chromatogr., 1992, 15, 545 CAS.
  8. Chiral Separations by Liquid Chromatography, ed. G. Subramaniam, VCH, Weinheim, 1994 Search PubMed.
  9. V. Schurig and H.-P. Nowotny, Angew. Chem., Int. Ed. Engl., 1990, 29, 939 CrossRef.
  10. W. A. Konig, B. Gehrcke, M. G. Peter and G. D. Prestwich, Tetrahedron: Asymmetry, 1993, 4, 165 CrossRef.
  11. K. B. Lipkowitz, S. Ragholhama and J. Young, J. Am. Chem. Soc., 1992, 114, 1554 CrossRef CAS; K. B. Lipkowitz, J. Chromatogr. A, 1995, 694, 15 CrossRef CAS.
  12. C. J. Easton and S. F. Lincoln, Chem. Soc. Rev., 1996, 24, 163 RSC.
  13. K. B. Lipkowitz, G. Pearl, B. Coner and M. A. Peterson, J. Am. Chem. Soc., 1997, 119, 600 CrossRef CAS.
  14. Examples of molecular dynamics simulations include: J. E. Kohler, M. Hohla, M. Richters and W. A. Kaing, Chem. Ber., 1994, 127, 119 Search PubMed; A. V. Eliseev, G. A. Iacobucci, N. A. Khanjin and F. M. Menger, J. Chem. Soc., Chem. Commun., 1994, 2051 CAS; M. E. Amato, G. M. Lombardo, G. C. Pappalardo and G. Scarlata, J. Mol. Struct., 1995, 350, 71 RSC see also: D. R. Black, C. G. Parker, S. S. Zimmerman and M. L. Lee, J. Comput. Chem., 1996, 17, 931 CrossRef CAS.
  15. (a) E. O. Stejskal and J. E. Tanner, J. Chem. Phys., 1965, 42, 285 CrossRef; (b) P. Stilbs, Progr. Nucl. Magn. Reson. Spectrosc., 1987, 19, 1 Search PubMed; (c) O. Soderman and P. Stilbs, Progr. Nucl. Magn. Reson. Spectrosc., 1994, 26, 480 Search PubMed.
  16. (a) O. Mayzel and Y. Cohen, J. Chem. Soc., Chem. Commun., 1994, 1901 RSC; (b) O. Mayzel, O. Aleksuike, F. Gnynszfan, S. E. Biali and Y. Cohen, J. Chem. Soc., Chem. Commun., 1995, 1183 RSC.
  17. A. Gafni and Y. Cohen, J. Org. Chem., 1997, 62, 120 CrossRef CAS.
  18. Cyclodextrins, ed. J. Szeitli and T. Osa, in Comprehensive Supramolecular Chemistry, ed. J. L. Atwood, J. E. D. MacNicol and F. Vogtle, vol. 3, Pergamon, Oxford, 1996 Search PubMed.
  19. G. C. Best and P. B. Dervan, J. Am. Chem. Soc., 1995, 117, 1187 CrossRef CAS.