The α-effect exhibited in gas-phase SN2@N and S N2@C reactions
Publication in refereed journal

香港中文大學研究人員
替代計量分析
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摘要In order to explore the existence of α-effect in gas-phase S N2@N reactions, and to compare its similarity and difference with its counterpart in SN2@C reactions, we have carried out a theoretical study on the reactivity of six α-oxy-Nus (FO-, ClO-, BrO-, HOO-, HSO-, H2NO-) in the SN2 reactions toward NR2Cl (R = H, Me) and RCl (R = Me, i-Pr) using the G2(+)M theory. An enhanced reactivity induced by the α-atom is found in all examined systems. The magnitude of the α-effect in the reactions of NR2Cl (R = H, Me) is generally smaller than that in the corresponding SN2 reaction, but their variation trend with the identity of α-atom is very similar. The origin of the α-effect of the SN2@N reactions is discussed in terms of activation strain analysis and thermodynamic analysis, indicating that the α-effect in the SN2@N reactions largely arises from transition state stabilization, and the "hyper-reactivity" of these α-Nus is also accompanied by an enhanced thermodynamic stability of products from the n(N) → σ*(O-Y) negative hyperconjugation. Meanwhile, it is found that the reactivity of oxy-Nus in the SN2 reactions toward NMe2Cl is lower than toward i-PrCl, which is different from previous experiments, that is, the SN2 reactions of NH2Cl is more facile than MeCl. © 2013 Wiley Periodicals, Inc.
著者Ren Y., Wei X.-G., Ren S.-J., Lau K.-C., Wong N.-B., Li W.-K.
期刊名稱Journal of Computational Chemistry
出版年份2013
月份9
日期5
卷號34
期次23
出版社John Wiley & Sons Inc.
出版地United States
頁次1997 - 2005
國際標準期刊號0192-8651
語言英式英語
關鍵詞activation strain analysis, NBO analysis, reactivity of oxy-nucleophile, α-effect in gas-phase SN2@N and SN2@C reactions

上次更新時間 2020-25-10 於 02:21