铜催化N-和O-arylation反应中依赖联体的选择性的替代机制解释
Hai-Zhu Yu1, Yuan-Ye Jiang, Yao Fu
1Department of Chemistry, Joint Laboratory of Green Synthetic Chemistry, University of Science and Technology of China, Hefei 230026, China.
Journal of the American Chemical Society
|December 8, 2010
概括
这项研究提出了另一种氧化添加/还原消除机制,以解释铜催化乌尔曼型反应中的依赖联体的选择性,为N-与O-arylation结果提供了新的见解.
科学领域:
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
- 反应机制 反应机制
背景情况:
- 乌尔曼型反应对于C-N和C-O键的形成至关重要.
- 之前的研究将铜催化反应中的依赖体的选择性归因于单电子转移和原子转移机制.
- 连带电荷和基质协调在决定反应路径中的作用仍然是积极研究的领域.
研究的目的:
- 调查乌尔曼型反应的另一种氧化添加/减少消除机制.
- 阐明不同的配体 (β-二基与1,10-) 如何影响反应选择性.
- 在铜催化中计算探索控制N-arylation与O-arylation的因素.
主要方法:
- 计算建模和理论计算.
- 过渡状态和反应能量学的分析.
- 拟议机制与现有的单电子转移通路的比较.
主要成果:
- 中性Cu(I) -β-二甲复合物在氨基醇协调之前促进了ArI的氧化添加,有利于N-arylation.
- 一个带正电荷的Cu ((I) -1,10-phenanthroline复合体需要基质去化以进行氧化添加,有利于O-arylation.
- 协调步骤是限制β-二二联体的速度,而氧化添加是限制1,10-类联体的速度.
结论:
- 氧化添加/还原消除机制为铜催化乌尔曼型反应中的依赖联体的选择性提供了可行的替代解释.
- 质物质的特性,特别是电荷,决定了反应机制和化 (N与O) 的首选部位.
- 了解这些机械细微差别是设计更高效和选择性催化系统的关键.
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