在静静的传递中,连接体的微妙平衡效应在静静的传递中起作用
Alireza Ariafard1, Brian F Yates
1Department of Chemistry, Faculty of Science, Central Tehran Branch, Islamic Azad University, Shahrak Gharb, Tehran, Iran. ariafard@yahoo.com
Journal of the American Chemical Society
|September 15, 2009
概括
连接物选择对静态反应的传播产生了关键影响. 重的连接体阻碍了协调,而小的连接体形成稳定的中间体,但三 (PPh3) 为高效的静止合提供了最佳的平衡.
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.
- 计算化学计算化学
背景情况:
- 斯蒂尔反应是有机合成中的一个关键的碳-碳键形成反应.
- 在催化剂上的体质量会影响转移的步骤,但最优的体设计仍然不清楚.
研究的目的:
- 用计算方法解决了用于催化静止反应的最佳连接体选择的困境.
- 阐明依赖连接体的传播率背后的机理原因.
主要方法:
- 用密度函数理论 (DFT) 的计算来建模催化循环.
- 对关键中间体和过渡状态的体和电子效应的分析.
主要成果:
- 非常重的带 (例如,PtBu3) 阻碍了器官间的协调.
- 小联体 (例如,PMe3) 导致稳定的中间体,具有高的激活能,用于传递.
- 三四 (PPh3) 提供平衡,促进协调,避免过于稳定的中间体.
- 化 (CsF) 通过通过计算阐明的机制加速转移.
- 对准确的理论预测而言,连接体的硬性属性至关重要.
结论:
- 三烯 (PPh3) 被确定为Stille反应的传递阶段的最佳配体.
- 计算研究突出了连接体体在催化剂设计中的重要性.
- 了解这些因素可以合理设计更高效的静态合反应.
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