一个黄金交换:一个可逆的,正式的乙烯插入到一个黄金(III) 氧键的机械研究
Eirin Langseth1, Ainara Nova, Eline Aa Tråseth
1Department of Chemistry and ‡Centre for Theoretical and Computational Chemistry (CTCC) Department of Chemistry, University of Oslo , P.O. Box 1033, Blindern, N-0315 Oslo, Norway.
Journal of the American Chemical Society
|June 20, 2014
概括
这项研究揭示了黄金 (III) 复合物如何与乙烯反应,形成新的黄金-碳键. 在TFA和TFE等酸性溶剂中,由于离子稳定,反应速度更快.
科学领域:
- 有机金属化学 有机金属化学
- 黄金催化剂的使用方法
- 反应机制 反应机制
背景情况:
- 黄金 (III) 复合物在催化中具有价值,但它们与烯酸的反应机制需要进一步阐明.
- 了解连接体解离和氨酸插入是设计高效的黄金催化反应的关键.
研究的目的:
- 为了研究Au(III) 复合物Au(OAc(F)) 2 ((tpy) 与乙烯的反应机制.
- 确定影响反应速度和产品选择性的因素.
- 探索溶剂和计算方法在理解反应途径中的作用.
主要方法:
- 金 (III) 复合物的合成和表征.
- 核磁共振 ((19) F NMR) 光谱法用于监测连接体解离.
- 用X射线结晶学来确定产品结构.
- 密度函数理论 (DFT) 计算 (PBE0-D3) 来阐明反应机制.
主要成果:
- (III) 复合物经历了一种乙酸连接体的可逆解离.
- 乙烯正式插入Au-O键,形成新的金-碳和氧-碳键.
- 与二甲 (CH2Cl2) 相比,三酸 (TFA) 和三乙醇 (TFE) 的反应速度明显更快.
- DFT计算表明,由乙烯攻击黄金中心启动的关联替换机制.
- 产品选择性是由动力学和热力学偏好控制的,有利于观察到的同位素.
结论:
- 反应通过一种关联置换机制进行,然后再插入olefin.
- 像TFA和TFE这样的溶剂通过稳定离开的酸盐连接体来加速反应.
- 这项研究提供了关于黄金 (III) 催化烯功能化的详细机制见解.
相关概念视频
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
10.9K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
10.9K
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
6.0K
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.
6.0K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
1.7K
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.
1.7K
01:08Types of Chemical Reactions: Exchange and Reversible
8.6K
An exchange reaction is a chemical reaction in which both synthesis and decomposition occur, chemical bonds are both formed and broken, and chemical energy is absorbed, stored, and released.
A special kind of exchange reaction is the oxidation-reduction reaction, or the redox reaction. These reactions involve the transfer of electrons from one compound to another. The electrons in these reactions commonly come from hydrogen atoms, which consist of an electron and a proton. A molecule gives up a...
A special kind of exchange reaction is the oxidation-reduction reaction, or the redox reaction. These reactions involve the transfer of electrons from one compound to another. The electrons in these reactions commonly come from hydrogen atoms, which consist of an electron and a proton. A molecule gives up a...
8.6K
02:36Oxymercuration-Reduction of Alkenes
8.1K
Oxymercuration–reduction of alkenes is one of the major reactions converting alkenes to alcohols. It involves the hydration of alkenes with mercuric acetate in a mixture of tetrahydrofuran and water, forming an organomercury adduct. This is followed by a demercuration step in which the adduct is reduced to an alcohol using sodium borohydride.
8.1K
03:00Preparation of Epoxides
7.6K
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy...
7.6K