CHIRAL RECOGNITION OF ETHERS BY NMR SPECTROSCOPY FHC-OCF2 CI FHC CF. 71 12 73 74 75 (R-enflurane) (R-isoflurane) (R-desflurane) Scheme 27.Structures of the ad three ur ted ethers(73-75)studied with cyclodextrins as CSA cH207 successi asuita ues con her NMR parameter which are not available from isotopic tially orientin talysis.Weinheim MR Here,a new field of research is ACKNOWLEDGMENTS 10.正 y.G.D supported by a fellowship granted to re t during thei ann E.edito many)D.B R tea 12. experim nts 13. R 14 rig V.Maver S.Sep on of ena for Xray se进 who suppli model compoun 2 ella vedova a (stanbul.Turk o oreto (La A2005:1068:1-30 nd) 17. Pietrusiewicz (Lublin. A200510831-57. K.M. 18.Na 19. LITERATURE CITED eak boson to the a-helix.Ber. gnition by mas 21. Chirality DOI 10.1002/chinries, CHA). Here, it is the mere shape of the chiral host rather than its polarity or ability to form binding interac￾tions which generates discrimination. Therefore, it is quite difficult to predict an experimental success if a suitable host system is to be selected from literature. Finally, some promising high-resolution solid-state NMR techniques are coming into the focus of chirality rec￾ognition studies.113,117–120 Here, further NMR parameters can be evaluated (e.g., crystal packing effects, chemical shift tensors, etc.), which are not available from isotopic liquid phase NMR. Both techniques, recording in partially orienting molec￾ular host systems and in the solid state, should be suc￾cessful in the enantiodifferentiation of ethers and many other unpolar compounds when isotropic liquid phase NMR spectroscopy fails. Here, a new field of research is opened for chiral discrimination. ACKNOWLEDGMENTS This work was supported by a fellowship granted to E.D.G. by the Deutscher Akademischer Austauschdienst (DAAD). H.D. is deeply indebted to S. Hameed, O. Kass￾ner, D. Magiera, S. Malik, J. Mattiza, C. Meyer, S. Moel￾ler, S. Rockitt, K. Wypchlo for their devoted cooperation in the Hannover dirhodium complex project during their PhD Theses. The author thanks D. Albert (Hannover, Germany), D. Baumann (Rostock, Germany), E. Hofer (Hannover, Germany), J. Jazwinski (Warsaw, Poland), and Z. Rozwadowski (Szczecin, Poland) for their skilled contri￾butions to so many sophisticated NMR experiments, G. To´ th, A. Simon, and T. Ga´ ti (Budapest, Hungary) for their invaluable help in variable-temperature NMR, R. Wartchow (Hannover, Germany) for X-ray diffraction measurements and, last but not least, to so many col￾leagues and friends who supplied model compounds: S. Antus (Debrecen, Hungary), T. Brotin (Lyon, France), J. Chojnowski (Lo´ dz, Poland), M. Cypryk (Lo´ dz, Poland), C. Della Ve´ dova (La Plata, Argentina), H. E. Di Loreto (La Plata, Argentina), I. Dogan (Istanbul, Turkey), J. Drabowicz (Lo´ dz, Poland), J. Frelek (Warsaw, Poland), J. Jios (La Plata, Argentina), K. Kiec-Konowicz (Krako´w, Poland), J. 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