由一个有机电子转移介质催化的未激活的烯酸的循环添加反应
Daesung Chong1, Michael Stewart, William E Geiger
1Department of Chemistry, University of Vermont, Burlington, Vermont 05405, USA.
Journal of the American Chemical Society
|May 26, 2009
概括
本研究介绍了一种快速的电化学方法,用于将循环烯酸转化为循环添加产品. 这种高效的过程,利用催化剂,为传统的光化学方法提供了更快的替代方案.
科学领域:
- 电化学 电化学 电化学
- 有机合成 有机合成
- 催化剂是一种催化剂.
背景情况:
- 循环烯酸是有机合成中的重要组成部分.
- 以前用于循环烯酸的循环添加反应的方法通常是缓慢和低效的.
- 光化学过程需要延长反应时间 (天) 来进行类似的转变.
研究的目的:
- 开发一种快速高效的电化学方法,用于从循环烯酸中合成循环添加产品.
- 用催化剂研究电催化循环添加的机制.
- 将电化学方法的效率和速度与现有的光化学路径进行比较.
主要方法:
- 在二甲中电化学氧化cis-cyclooctene (COE) 使用特定的电解质和催化剂 (ReCp(CO) ((3)).
- 应用1.25V的电位与铁相对应,以启动反应.
- 对反应产品的分析,包括三环二甲的二聚体混合物.
主要成果:
- 顺利将cis-cyclooctene转化为一个C(8) - - 模体 (三环二甲基) 与一个主要的cis-anti-cis同位素.
- 证明了循环添加产品与较小的循环烯酸 (C(5) -C(7) 的形成.
- 确定反应是通过介质 (1(+)) 和根链机制的电生成进行的,需要低电荷 (0.1 F/olefin).
- 在几分钟内实现了完整的转化,比一周的光化学方法快得多.
结论:
- 开发的电化学过程为循环烯循环添加提供了更快,更有效的途径.
- 该方法是多用途的,适用于各种周期性烯酸.
- 这种电催化方法为循环添加产品的光化学合成提供了可持续和快速的替代方案.
相关概念视频
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
Cycloaddition Reactions: Overview
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
Olefin Metathesis Polymerization: Overview
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Cycloaddition Reactions: MO Requirements for Thermal Activation
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.


