在环境温度下对非循环性乙烯基因和乙烯基因进行以为媒介的循环芳化
Joseph M O'Connor1, Seth J Friese, Mark Tichenor
1Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA. jmoconno@ucsd.edu
Journal of the American Chemical Society
|April 4, 2002
概括
(II) 离子[Cp*Ru(NCMe) 3]OTf在室温下催化了非循环乙烯基因的伯格曼循环芳香化. 研究支持一种p-中间途径,与 - 乙烯机制不同.
科学领域:
- 有机金属化学 有机金属化学
- 有机合成 有机合成
- 催化剂是一种催化剂.
背景情况:
- 伯格曼循环芳香化和Hopf循环循环的非循环enediynes和dienynes通常需要高温 (150-250°C).
- 鲁复合体在较温和的条件下提供催化这些转换的潜力.
研究的目的:
- 为了研究一种特定的 ((II) 离子,[Cp*Ru ((NCMe) 3) OTf,在促进循环芳香化反应中的催化活性.
- 阐明反应机制,包括确定关键中间体.
主要方法:
- 各种非循环乙基因和一种联合二基因与THF或CDCl3中的[Cp*Ru(NCMe) 3OTf在室温或100°C下发生反应.
- 使用包括X射线晶体学在内的技术,对由此产生的鲁烯复合物的表征.
- 标记研究探讨反应机制.
主要成果:
- (II) 复合物在室温下有效地催化了非循环乙烯和合二烯的循环芳香化,产生烯复合物.
- 观察到各种替代二二的形成产量很高,包括[Cp*Ru{(3a,4,5,6,7,7a-eta) -2,3-二-5,6-二-1H-二}]OTf和相关的西兰替代产品.
- 标记实验提供了支持p-中间体的证据,但不包括-乙烯通路.
结论:
- 鲁 (II) 离子[Cp*Ru (NCMe) ]3OTf 是一种高效的催化剂,可以在温和条件下进行非循环恩迪因和相关循环的伯格曼循环芳香化.
- 反应通过p-中间体进行,为催化循环芳香化提供了新的机械洞察力.
- 与未催化热反应相比,这种催化系统显著降低了这些转换的激活能量.
相关概念视频
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.
[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.
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
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...
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.


