10.1021/jp900576x.s001
Suk Im
Suk
Im
Sung-Woo Jang
Sung-Woo
Jang
Hye-Rim Kim
Hye-Rim
Kim
Young-Ho Oh
Young-Ho
Oh
Sung-Woo Park
Sung-Woo
Park
Sungyul Lee
Sungyul
Lee
Dae Yoon Chi
Dae Yoon
Chi
A Mechanistic Study of S<sub>N</sub>2 Reaction in a Diol Solvent
American Chemical Society
2009
protic
cation
SN 2 Reaction
hydroxyl groups act
ethylene glycol
353K
SN 2 reactions
nucleophile
OH
Lewis
ethylene glycol manifests
2009-04-16 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/A_Mechanistic_Study_of_S_sub_N_sub_2_Reaction_in_a_Diol_Solvent/2863453
We present calculations for the mechanism of S<sub>N</sub>2 reactions in ethylene glycol, focusing on the role of two protic functional groups (−OH) in the solvent molecule. We find that some hydroxyl groups act as Lewis base to interact with the cation, whereas others affect the reaction as Lewis acid to the nucleophile. We predict that the nucleophile (F<sup>−</sup>) reacts as an ion pair rather than as a solvent-separated ion when metal cation (Cs<sup>+</sup>) is used as a counterion. The overall influence of ethylene glycol manifests itself as the reaction barrier (<i>E</i><sup>⧧</sup> = 20.0, <i>G</i><sub>353K</sub><sup>⧧</sup> = 21.5 kcal/mol) that is a bit smaller than that in <i>tert</i>-butyl alcohol, which proved to be a very efficient solvent for S<sub>N</sub>2 reactions [Kim, D. W., et al. J. Am. Chem. Soc. 2006, 128, 16394]. We therefore show that a small protic solvent such as ethylene glycol may be as efficient as a bulky alcohol for S<sub>N</sub>2 reactions.