Effect of electron-withdrawing group on the [3,3]-sigmatropicrearrangements of 1,5-enynes, 1,5-diynes and 1,2-diene-5-ynes: Atheoretical study

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	Effect of electron-withdrawing group on the [3,3]-sigmatropicrearrangements of 1,5-enynes, 1,5-diynes and 1,2-diene-5-ynes: Atheoretical study
	Xia, Yuanzhi; Zhou, Fengying; Li, Yahong; Lia, Wu
	2009
发表期刊	JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM
ISSN	0166-1280
卷号	904 期号:1-3 页码:69-73
关键词	Cope Rearrangement Electronic Effect Theoretical Calculation
语种	The electronic effects of an electron-withdrawing group (exemplified by formyl group) on the kinetic and thermodynamic aspects of substituted 1,5-enyne. 1,5-diyne, and 1,2-diene-5-yne Cope rearrangements were investigated by means of DFT and CBS-QB3 calculations. The energy barriers of the formyl substituted reactions are lower than those of the unsubstituted ones almost in all cases, and the barriers will be further lowered when catalyzed by ACl(3), The most obvious electronic effect was calculated for the C-2 formyl substituted 1,5-enyne rearrangements, which have activation barriers of 27.1 and 18.1 kcal/mol, respectively, for the uncatalyzed and catalyzed reactions. The charge transfer induced by the electron-withdrawing group and stabilization of the charge by Lewis acid are responsible for the different energetic profiles. The formyl substitution will change the thermodynamic profiles of the transformations, notablely, increase the reaction enthalpies of the 1,5-diyne and 1,2-diene-5-yne rearrangements by over 5.0 kcal/mol, as result of the stabilization effect of a formyl substitution attached directly to the unsaturated moieties of the products. (c) 2009 Elsevier B.V. All rights reserved. The electronic effects of an electron-withdrawing group (exemplified by formyl group) on the kinetic and thermodynamic aspects of substituted 1,5-enyne. 1,5-diyne, and 1,2-diene-5-yne Cope rearrangements were investigated by means of DFT and CBS-QB3 calculations. The energy barriers of the formyl substituted reactions are lower than those of the unsubstituted ones almost in all cases, and the barriers will be further lowered when catalyzed by ACl(3), The most obvious electronic effect was calculated for the C-2 formyl substituted 1,5-enyne rearrangements, which have activation barriers of 27.1 and 18.1 kcal/mol, respectively, for the uncatalyzed and catalyzed reactions. The charge transfer induced by the electron-withdrawing group and stabilization of the charge by Lewis acid are responsible for the different energetic profiles. The formyl substitution will change the thermodynamic profiles of the transformations, notablely, increase the reaction enthalpies of the 1,5-diyne and 1,2-diene-5-yne rearrangements by over 5.0 kcal/mol, as result of the stabilization effect of a formyl substitution attached directly to the unsaturated moieties of the products. (c) 2009 Elsevier B.V. All rights reserved.
文献类型	期刊论文
条目标识符	http://ir.isl.ac.cn/handle/363002/2102
专题	青海盐湖研究所知识仓储
推荐引用方式 GB/T 7714	Xia, Yuanzhi,Zhou, Fengying,Li, Yahong,et al. Effect of electron-withdrawing group on the [3,3]-sigmatropicrearrangements of 1,5-enynes, 1,5-diynes and 1,2-diene-5-ynes: Atheoretical study[J]. JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM,2009,904(1-3):69-73.
APA	Xia, Yuanzhi,Zhou, Fengying,Li, Yahong,&Lia, Wu.(2009).Effect of electron-withdrawing group on the [3,3]-sigmatropicrearrangements of 1,5-enynes, 1,5-diynes and 1,2-diene-5-ynes: Atheoretical study.JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM,904(1-3),69-73.
MLA	Xia, Yuanzhi,et al."Effect of electron-withdrawing group on the [3,3]-sigmatropicrearrangements of 1,5-enynes, 1,5-diynes and 1,2-diene-5-ynes: Atheoretical study".JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM 904.1-3(2009):69-73.