通过C-H...O键识别素基质:适用于不对称的Pauson-Khand反应
Jordi Solà1, Antoni Riera, Xavier Verdaguer
1Unitat de Recerca en Síntesi Asimètrica (URSA-PCB), Parc Científic de Barcelona and Departament de Química Orgànica, Universitat de Barcelona, c/Josep Samitier, 1-5, E-08028 Barcelona, Spain.
Journal of the American Chemical Society
|September 30, 2005
概括
在PuPHOS和CampPHOS配体中,有一种独特的甲部分作为键捐赠体. 这种相互作用驱动了二聚选择性联结体交换,使得具有高反选择性的不对称的Pauson-Khand反应成为可能.
科学领域:
- 有机金属化学 有机金属化学
- 有机合成 有机合成
- 超分子化学 超分子化学
背景情况:
- 干的设计对于控制催化反应中的立体选择性至关重要.
- 键相互作用,特别是非经典的C-H...O键,越来越多地被认为是它们在分子识别和指导化学转换中的作用.
- 帕森 - 坎德反应是构建环氨环的强大工具,但实现高反选择性仍然是一个挑战.
研究的目的:
- 为了研究PuPHOS和CampPHOS配体中独特的甲部分作为键捐赠者的作用.
- 为了证明这种结相互作用在实现二聚体选择性连接体交换中的应用.
- 为了利用这种二分体选择性过程来进行不对称的分子间Pauson-Khand反应.
主要方法:
- 进行X射线晶体学以分析结合相互作用.
- 质子核磁共振 (1H NMR) 谱学用于研究连接体交换过程.
- 量子力学计算以阐明C-H...O键的性质和强度.
主要成果:
- 在PuPHOS和CampPHOS配体中发现了一种独特的甲部分,被确定为一种强大的键供体.
- 甲和氨基碳酸受体之间的非经典键促进了高度二选择性的配体交换.
- 通过实验和计算分析,这种相互作用被描述为强大的C-H...O键.
- 这种以键为导向的配体交换成功应用于不对称的分子间帕森 - 坎德反应,产生高达94%的反原子过剩 (ee) 的产物.
结论:
- 在PuPHOS和CampPHOS连接体中的甲部分作为一种强大的键捐赠体,使得在连接体交换中可预测的 diastereoselectivity.
- 这种超分子相互作用为控制有机金属转换中的立体化学提供了一种新的策略.
- 开发的方法提供了一条有效的途径,通过不对称的Pauson-Khand反应,通过异构丰富的循环添加物.
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