首页> 外文期刊>The Journal of Organic Chemistry >Theoretical Investigations toward the [4 + 2] Cycloaddition of Ketenes with N?Benzoyldiazenes Catalyzed by N?Heterocyclic Carbenes: Mechanism and Enantioselectivity
【24h】

Theoretical Investigations toward the [4 + 2] Cycloaddition of Ketenes with N?Benzoyldiazenes Catalyzed by N?Heterocyclic Carbenes: Mechanism and Enantioselectivity

机译:N?杂环卡宾催化N-苯甲酰二氮烯酮与[4 + 2]环加成反应的理论研究:机理和对映选择性

获取原文
获取原文并翻译 | 示例
       

摘要

Density functional theory (DFT) calculationsnhave been performed to provide the first detailed computationalnstudy on the mechanism and enantioselectivity for the [4n+ 2] cycloaddition reaction of ketenes with N-benzoyldiazenesncatalyzed by N-heterocyclic carbenes (NHCs). Two possiblenmechanisms have been studied: first is the “ketene-first”nmechanism (mechanism A), and second is the novel “diazenefirst”nmechanism (mechanism B). The calculated results reveal that mechanism B is more favorable than mechanism A because itnis not only of lower energy barrier but also more consistent with the provided general experimental procedure (Huang, X.-L.; He,nL.; Shao, P.-L.; Ye, S. Angew. Chem., Int. Ed. 2009, 48, 192−195). The enantioselectivity-determining step is demonstrated tonpresent during the first process of cycloaddition, and the main product configuration is verified to agree with the experimental eenvalues very well. This study should be of some worth on forecasting how different substituent groups of catalysts and/or reactantsnaffect the enantioselectivity of products. The obtained novel mechanistic insights should be valuable for not only rational designnof more efficient NHC catalysts but also understanding the general reaction mechanism of [4 + 2] cycloaddition of ketenes.
机译:已经进行了密度泛函理论(DFT)计算,以提供有关N杂环卡宾(NHC)催化的乙烯酮与N-苯甲酰二氮烯的[4n + 2]环加成反应的机理和对映选择性的第一个详细的计算研究。研究了两种可能的机制:第一是“乙烯酮优先”机制(机制A),第二是新颖的“二烯优先”机制(机制B)。计算结果表明,机理B比机理A更有利,因为它不仅具有较低的能垒,而且与所提供的一般实验程序更加一致(Huang,X.-L .; He,nL .; Shao,P.- L .; Ye,S.Angew.Chem。,Int。Ed。2009,48,192-195)。对映选择性确定步骤在环加成的第一个过程中被证明是同时存在的,并且验证了主要产物构型与实验值非常吻合。这项研究对于预测催化剂和/或反应物的不同取代基如何影响产物的对映选择性具有一定的价值。所获得的新颖的力学见解不仅对于合理设计更有效的NHC催化剂,而且对于[4 + 2]烯酮环加成反应的一般反应机理均具有参考价值。

著录项

  • 来源
    《The Journal of Organic Chemistry》 |2012年第23期|10729-10737|共9页
  • 作者单位

    The College of Chemistry and Molecular Engineering Zhengzhou University Zhengzhou Henan Province 450001 P. R. China;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 13:29:33

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号