通过修改三醇衍生的碳联体来定制C-H氨化活性
Luke A Hudson1, Wowa Stroek1, Martin Albrecht1
1Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012, Bern, Switzerland. martin.albrecht@unibe.ch.
Dalton transactions (Cambridge, England : 2003)
|August 20, 2024
概括
新的铁催化剂具有庞大的配体,有效地将有机亚化物转化为罗利丁. 增加三利烯配体的固体体积可以使选择性提高到99%以上,同时稍微降低反应速率.
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.
- 有机合成 有机合成
背景情况:
- 铁复合物越来越多地被探索为可持续的催化剂.
- C-H氨基化是有机合成中的关键转化.
- 三聚乙烯-酸联体具有可调节的固态和电子特性.
研究的目的:
- 为了合成和表征新的铁 (II) 复合物,使用硬质要求高的C,O-双酸化三利烯-酸联体.
- 评估这些复合物的催化活性和选择性在有机亚酸盐的分子内C-H氨基化中.
- 阐明由连接体 steric bulk 影响的机械方面.
主要方法:
- 新型二醇烯 (dipp) 和亚达曼 (Ad) 替代的三聚烯酸联体的合成.
- 与铁 (II) 的金属化形成[Fe (C) O) 2]复合体.
- 催化测试有机亚酸的分子内C-H氨化.
- 动力学研究和机械学分析.
主要成果:
- 两种新的铁 (II) 复合物[Fe (C^O) 2]通过使用dipp和Ad替代联结物成功合成.
- 这两种复合物在有机亚酸的分子内C-H氨化中都表现出高活性.
- 增加了dipp和Ad连体的硬质体积,与梅西 (Mes) 模拟物 (92%) 相比,显著提高了对pyrrolidine形成的选择性 (>99%).
- 动力学研究显示,铁复合物度与铁复合物度有半级的依赖性,这表明铁复合物处于二金属静止状态.
结论:
- 在铁上立阻的三利烯-酸连接体 (((II) 催化剂促进高度选择性的分子内C-H氨基化.
- 增强的联结体似乎不利于不必要的N2损失和烯形成,同时保护烯中间体,从而导致更高的选择性.
- 这些发现为这些催化系统中活动和选择性之间的观察到的权衡提供了机制的理由.
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