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タイトル: Presence or absence of a novel charge-transfer complex in the base-catalyzed hydrolysis of N-ethylbenzamide or ethyl benzoate.
著者: Yamabe, Shinichi
Guan, Wei
Sakaki, Shigeyoshi
著者名の別形: 山邊, 信一
キーワード: basic hydrolyses
DFT calculations
ethyl benzoate
N-ethylbenzamide
reactive intermediates
transition states
発行日: Jan-2013
出版者: Beilstein-Institut
誌名: Beilstein journal of organic chemistry
巻: 9
開始ページ: 185
終了ページ: 196
抄録: Reaction paths of base-catalyzed hydrolyses of isoelectronic substrates, Ph-C(=O)-X-Et [X = O (ethyl benzoate) and X = NH (N-ethylbenzamide)], were traced by DFT calculations. To simulate bond interchanges accompanied by proton transfers, a cluster model of Ph-C(=O)-X-Et + OH(-)(H(2)O)(16) was employed. For X = O, three elementary processes and for X = NH four ones were obtained. The rate-determining step of X = O is the first TS (TS1, the OH(-) addition step), while that of X = NH is TS2. TS2 of X = NH leads to a novel Mulliken charge-transfer complex, Ph-(OH)(O=)C∙∙∙N(H(2))-Et. The superiority or inferiority between the direct nucleophilic process or the general base-catalyzed process for TS1 was examined with the model Ph-C(=O)-X-Et + OH(-)(H(2)O)(n), n = 3, 5, 8, 12, 16, 24 and 32. The latter process was calculated to be more favorable regardless of the number (n, except n = 3) of water molecules. The counter ion Na(+) works unfavorably on the ester hydrolysis, particularly on TS1. A minimal model of TS1 was proposed and was found to be insensitive to n.
著作権等: © 2013 Yamabe et al; licensee Beilstein-Institut.
This is an Open Access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The license is subject to the Beilstein Journal of Organic Chemistry terms and conditions: (http://www.beilstein-journals.org/bjoc)
URI: http://hdl.handle.net/2433/171151
DOI(出版社版): 10.3762/bjoc.9.22
PubMed ID: 23400273
出現コレクション:学術雑誌掲載論文等

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