(I) 与基过氧化物的反应: (II) - 氧化物,基基和催化C-H乙化
Raymond T Gephart1, Claire L McMullin, Nicholas G Sapiezynski
1Department of Chemistry, Georgetown University, Box 571227-1227, Washington, D.C. 20057, USA.
Journal of the American Chemical Society
|September 27, 2012
概括
铜 (I) 催化剂促进了三丁氧化的激活,产生了三丁基. 这些基因使得在温和的条件下能够有效的催化C-H乙化环素.
科学领域:
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
- 激进化学 激进化学是什么
背景情况:
- 铜 (I) 复合物是有机合成中的多功能催化剂.
- 过氧化物激活对于产生反应性基因物种至关重要.
- C-H功能化提供了一条直接通往有价值的有机化合物的途径.
研究的目的:
- 为了研究铜(I) β-二甲基胺酸和有机过氧化物之间的反应机制.
- 为了探索氧基的生成和反应性.
- 开发一种利用铜和过氧化物进行C-H乙化的催化系统.
主要方法:
- 铜的动力分析 (I) 复杂反应与三丁氧化和二甲氧化.
- 计算建模以阐明过氧化物激活途径.
- 使用环素和三丁氧化的催化C-H乙化实验.
主要成果:
- 对过氧化物反应观察到的第一阶动力学,表明自由基的形成.
- 识别新型的过氧化铜添加物和一个短暂的Cu (III) 物种.
- 在室温下成功的催化C-H乙化循环素产生三乙烯循环乙烯以60%的产量.
结论:
- 铜 (I) 复合物通过激素通路有效地激活有机过氧化物.
- 生成的三丁基可以用于催化C-H乙化.
- 这项研究提出了一种新且高效的合成以太的方法.
相关概念视频
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.
Preparation of Epoxides
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 acids to...
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 acids to...
Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
The radical dimerization of ketones or aldehydes gives vicinal diols through a pinacol coupling reaction. However, the behavior of titanium metals used for the reaction as a source of electrons is unusual. When the reaction is carried out in the presence of titanium, diols can be isolated at low temperatures. Else titanium further reacts with diols, forming alkenes through the McMurry reaction.
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
Baeyer–Villiger oxidation converts aldehydes to carboxylic acids and ketones to esters. The reaction uses peroxy acids or peracids and is often catalyzed by acid. The reaction is named after its pioneers, Adolf von Baeyer and Victor Villiger. The reaction is achieved by a wide range of peracids such as m-chloroperoxybenzoic acid (mCPBA), perbenzoic acid (C6H5COOOH), peracetic acid (CH3COOOH), hydrogen peroxide (H2O2), and tert-butyl hydroperoxide (t-BuOOH).
The carbonyl center is activated by...
The carbonyl center is activated by...
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
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.
Electrophilic Addition to Alkynes: Hydrohalogenation
Electrophilic addition of hydrogen halides, HX (X = Cl, Br or I) to alkenes forms alkyl halides as per Markovnikov's rule, where the hydrogen gets added to the less substituted carbon of the double bond. Hydrohalogenation of alkynes takes place in a similar manner, with the first addition of HX forming a vinyl halide and the second giving a geminal dihalide.
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