期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 139, 期 46, 页码 16650-16656出版社
AMER CHEMICAL SOC
DOI: 10.1021/jacs.7b07988
关键词
-
资金
- National Science Foundation (NSF) [CHE-1361104, CHE-1464690]
- NSF under the CCI Center for Selective C-H Functionalization [CHE-1205646]
- National Natural Science Foundation of China [21173082]
- China Scholarship Council (CSC)
- NSF [OCI-1053575]
- Supercomputer Center at East China Normal University
- Direct For Mathematical & Physical Scien
- Division Of Chemistry [1361104] Funding Source: National Science Foundation
- Direct For Mathematical & Physical Scien
- Division Of Chemistry [1205646] Funding Source: National Science Foundation
The selectivities in C-H oxidations of a variety of compounds by DMDO have been explored with density functional theory. There is a linear Evans-Polanyi-type correlation for saturated substrates. Activation energies correlate with reaction energies or, equivalently, BDEs (Delta H-sat(double dagger) = 0.91*BDE - 67.8). Unsaturated compounds, such as alkenes, aromatics, and carbonyls, exhibit a different correlation for allylic and benzylic C-H bonds (Delta H-unsat(double dagger) = 0.35*BDE - 13.1). Bernasconi's Principle of Non-Perfect Synchronization (NPS) is found to operate here. The origins of this phenomenon were analyzed by a Distortion/Interaction model. Computations indicate early transition states for H-abstractions from allylic and benzylic C-H bonds, but later transition states for the saturated. The reactivities are mainly modulated by the distortion energy and the degree of dissociation of the C-H bond. While the increase in barrier with higher BDE is not unexpected from the Evans-Polanyi relationship, two separate correlations, one for saturated compounds, and one for unsaturated leading to delocalized radicals, were unexpected.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据