The influence of solvation and finite temperatures on the Wittig reaction: A theoretical study

Seth, M., Senn, H.M. and Ziegler, T. (2005) The influence of solvation and finite temperatures on the Wittig reaction: A theoretical study. Journal of Physical Chemistry A, 109(23), pp. 5136-5143. (doi: 10.1021/jp045318i)

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Abstract

The effects of the solvent and finite temperature (entropy) on the Wittig reaction are studied by using density functional theory in combination with molecular dynamics and a continuum solvation model. Standard gas-phase zero-temperature calculations are found to give similar results to previous studies. Gas-phase dynamics simulations allow the free energy profile of the reaction to be calculated through thermodynamic integration. The free energy profile is found to have a significant entropic barrier to the addition step of the reaction where only a small barrier was present in the potential energy curve. The introduction of the solvent dimethyl sulfoxide causes a change in the structure of the intermediate from the oxaphosphetane structure to the dipolar betaine structure. The overall reaction energy is changed only slightly. When the effects of both entropy and the solvent are included a significant entropic barrier to the addition reaction is obtained and the predicted intermediate again has the betaine structure.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Senn, Dr Hans
Authors: Seth, M., Senn, H.M., and Ziegler, T.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:Journal of Physical Chemistry A
Publisher:American Chemical Society
ISSN:1089-5639
ISSN (Online):1520-5215
Published Online:19 May 2005

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