Intramolecular OH⋅⋅⋅FC Hydrogen Bonding in Fluorinated Carbohydrates: CHF is a Better Hydrogen Bond Acceptor than CF2

Authors

  • Dr. Guy T. Giuffredi,

    1. Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road OX1 3TA Oxford (UK)
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  • Prof. Véronique Gouverneur,

    Corresponding author
    1. Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road OX1 3TA Oxford (UK)
    • Véronique Gouverneur, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road OX1 3TA Oxford (UK)

      Bruno Bernet, Laboratorium für Organische Chemie, ETH Zürich, Wolfgang Pauli Strasse 10, 8093 Zürich (Switzerland)

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  • Dr. Bruno Bernet

    Corresponding author
    1. Laboratorium für Organische Chemie, ETH Zürich, Wolfgang Pauli Strasse 10, 8093 Zürich (Switzerland)
    • Véronique Gouverneur, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road OX1 3TA Oxford (UK)

      Bruno Bernet, Laboratorium für Organische Chemie, ETH Zürich, Wolfgang Pauli Strasse 10, 8093 Zürich (Switzerland)

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  • We thank Prof. B. Jaun, Dr. B. W. Schweizer (both ETH Zürich), Dr. T. D. W. Claridge, Dr. B. Odell, and Dr. A. L. Thompson (all University of Oxford) for helpful advices concerning NMR spectroscopy and X-ray crystallography, and the Berrow Foundation for a scholarship to G.T.G.

Abstract

original image

An intramolecular bifurcated H-bond from the axial HO-2 group to the axial F-4 atom and to the O5 atom of α-D-hexopyranosides in apolar solvents is evidenced in 1H NMR spectra. The H-accepting properties of the F atom are modulated by the orientation of the O-substituent at the C3 atom and by an additional F atom at the C4 atom (see picture).

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