28 research outputs found

    Characterization of the tautometric equilibrium of triazolium ylids by NMR spectroscopy

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    The monitoring by 1H NMR of the kinetics of the tautomeric equilibrium between the triazolium ylids lf-h and 2f-h confirms the existence of a dynamic equilibrium and corroborates the results obtained by the chemically induced perturbation of the equilibrimn

    Conformational study of glycal-type neuraminidase inhibitors

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    International audienceConformational study of glycal-type neuraminidase inhibitors The conformational flexibility of two glycal-type neuraminidase inhibitors has been studied, using several molecular modeling techniques. In agreement with the experimental data available, an intramolecular hydrogen bond, representing a key structural feature that controls the conformer distribution in solution, has been identified. The contribution of each substituent on the overall equilibrium was evaluated using simplified derivatives. Additionally, four methods for estimating NMR coupling constants from dihedral angles were evaluated and the Haasnoot method was found to be appropriate for this class of sugars. These results should allow a better understanding of the structural parameters governing physico-chemical properties of glycal-like compounds
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