易斯酸辅助C(sp3) -C(sp3) 减少淘汰在黄金
Cyril A Theulier1, Yago García-Rodeja2, Karinne Miqueu2
1CNRS/Université Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA, UMR 5069), 118 Route de Narbonne, 31062 Cedex 09 Toulouse, France.
Journal of the American Chemical Society
|May 3, 2023
概括
一种新型的氨酸联体 (1-Fxyl) 便于从黄金复合物中减少乙. 这种易斯酸辅助的途径通过zwitterionic中间体显著降低了激活能量,提高了C-C合效率.
科学领域:
- 有机金属化学
- 催化剂
- 计算化学
背景情况:
- 减少消除是许多涉及金属复合物的催化循环中的关键步骤.
- 酸化合物正在成为具有可调节电子特性的多功能联体.
- 了解反应机制对于设计高效的催化系统至关重要.
研究的目的:
- 研究一种特定的素联体 (1-Fxyl) 在促进从黄金复合体中减少乙的作用.
- 阐明这种易斯酸辅助反应的机械路径和能量概况.
- 探索连接体结构和反应条件对催化活性的影响.
主要方法:
- 素-联体1-Fxyl的合成和表征
- 通过核磁共振 (NMR) 光谱来实验减少消除反应的监测.
- 密度功能理论 (DFT) 计算以确定反应途径,中间体和激活障碍.
- 内在键轨 (IBO) 分析以了解电子特征.
主要成果:
- 氨基1-Fxyl促进了从[AuMe2(μ-Cl]2中减少乙的去除.
- 核磁共振研究证实了 (1-Fxyl) AuMe2Cl中间体的形成.
- DFT计算显示,通过易斯酸介导的化物抽取促进了较低能量的化物通路 (10 kcal/mol以上的激活屏障减少).
- 在最后一步中,化物从转移到黄金.
结论:
- 素中中心的易斯酸度对于通过还原性消除实现C(sp3) -C(sp3) 合至关重要.
- 配体的两性性质在激活黄金中心中起着至关重要的作用.
- 优化易斯酸度和控制化物度是高效的黄金催化C-C键形成的关键.
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