由阴性比索克萨 (BOX) 连接体支持的尼克尔-伊米尼尔复合体催化的 C-H 氨化
Yuyang Dong1, Colton J Lund2, Gerard J Porter1
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States.
一种新的性催化剂能够产生选择性C-H氨基化,产生类似于pyrrolidines的中等产量和选择性 (ee) 的N-异环. 该研究揭示了催化机制的关键步骤,包括H原子抽象和基因重组,影响产品的形成.
科学领域:
- 有机金属化学
- 不对称的催化
- 合成有机化学
背景情况:
- 在非对称催化中,奇拉尔比索索林 (TrHBOX) 配体具有价值.
- 复合物越来越多地被用于C-H功能化反应.
- 闭环氨化是N-异环合成的关键转化.
研究的目的:
- 开发一种性催化剂,用于对C-H的选择性氨化.
- 研究催化分子内C-H氨化机制.
- 合成具有高反选择性的奇拉性罗利丁衍生物.
主要方法:
- 合成三替代的比索 (TrHBOX) 连接物及其复合物.
- 使用X射线晶体学,NMR和EPR光谱学对中间体进行表征.
- 用各种基质进行酶选择性分子内C-H氨基化反应.
- 动力学研究和乳标记以阐明反应机制.
主要成果:
- 单价复合物 (TrHBOX) Ni(py) 催化了亚齐多的分子内C-H氨基化.
- 罗利丁产品的产量为29% - 87%
- 动力学研究表明H原子抽象步骤具有不对称的过渡状态.
- 通过H原子抽象和基因重组步骤来确定酶选择性.
结论:
- 开发的性催化剂对对抗选择性C-H氨化有效.
- 反应机制涉及不同的因子决定步骤.
- 具有良好的产量和中等效果的2,5- bis- tertiary pyrrolidines的催化酶选择合成.
更多相关视频
09:37Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry
Published on: October 18, 2019
07:20Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
相关概念视频
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Preparation of Amines: Reduction of Amides and Nitriles
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Nitriles to Amines: LiAlH4 Reduction
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
