×
验证码:
换一张
忘记密码?
记住我
×
登录
中文版
|
English
中国科学院青海盐湖研究所机构知识库
Knowledge Management System Of Qinghai Institute of Salt Lakes,CAS
登录
注册
ALL
ORCID
题名
作者
学科领域
关键词
资助项目
文献类型
出处
收录类别
出版者
发表日期
存缴日期
学科门类
学习讨论厅
粘贴图片网址
首页
研究单元&专题
作者
文献类型
学科分类
知识图谱
新闻&公告
在结果中检索
研究单元&专题
青海盐湖研究所知识仓... [1]
作者
文献类型
期刊论文 [1]
发表日期
2009 [1]
语种
The electr... [1]
出处
JOURNAL OF... [1]
资助项目
收录类别
资助机构
×
知识图谱
ISL OpenIR
开始提交
已提交作品
待认领作品
已认领作品
未提交全文
收藏管理
QQ客服
官方微博
反馈留言
浏览/检索结果:
共1条,第1-1条
帮助
限定条件
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.
已选(
0
)
清除
条数/页:
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
排序方式:
请选择
题名升序
题名降序
期刊影响因子升序
期刊影响因子降序
提交时间升序
提交时间降序
作者升序
作者降序
WOS被引频次升序
WOS被引频次降序
发表日期升序
发表日期降序
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
期刊论文
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, 2009, 卷号: 904, 期号: 1-3, 页码: 69-73
作者:
Xia, Yuanzhi
;
Zhou, Fengying
;
Li, Yahong
;
Lia, Wu
收藏
  |  
浏览/下载:252/0
  |  
提交时间:2013/10/07
Cope Rearrangement
Electronic Effect
Theoretical Calculation