- - 催化地用乙氧基替代propargylic类型的
Isamu Matsuda1, Ken-ichi Komori, Kenji Itoh
1Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan. matsudai@apchem.nagoya-u.ac.jp
Journal of the American Chemical Society
|August 1, 2002
概括
这项研究引入了一种新的催化反应在propargylic乙酸和enoxysilanes之间,有效地产生β-alkynyl. 该方法为各种基质提供了高产量和选择性,使新的合成途径成为可能.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 合成方法论 合成方法论
背景情况:
- 基化合物是多功能合成中间体.
- 在有机合成中,合成β-基尼基的高效方法是有价值的.
- 催化为C-C键形成提供了独特的反应性.
研究的目的:
- 开发一种用于合成β-基基的新型催化系统.
- 为了研究propargylic类型酸盐与酸的反应性.
- 探索开发的反应的范围和选择性.
主要方法:
- 作为催化剂使用了1mol%的[Ir(cod) {P(OPh) 3}2]OTf.
- 用分子 (H2) 激活了催化剂.
- 在优化条件下,与氧烯酸盐反应的propargylic类型酸盐.
主要成果:
- 取得了高至优异的β-基尼基的产量.
- 已证明大多数基乙烯的基碳的排他性或选择性替代.
- 观察到在甲基碳上有两个基时,甲基产品的形成占主导地位.
结论:
- 开发的催化反应是合成β-基尼尔基的一个有效方法.
- 反应表现出基于基质结构的区域选择性的良好控制.
- 这种方法为访问复杂的基化碳化合物提供了有价值的工具.
相关概念视频
Organic Compounds
All living things are formed mostly of carbon compounds called organic compounds. The category of organic compounds includes both natural and synthetic compounds that contain carbon. Although a single, precise definition has yet to be identified by the chemistry community, most agree that a defining trait of organic molecules is the presence of carbon as the principal element, bonded to hydrogen and other carbon atoms. However, some carbon-containing compounds such as carbonates, cyanides, and...
Alkynes to Aldehydes and Ketones: Acid-Catalyzed Hydration
Introduction
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
Analogous to alkenes, alkynes also undergo acid-catalyzed hydration. While the addition of water to an alkene gives an alcohol, hydration of alkynes produces different products such as aldehydes and ketones.
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
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...
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...
Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...


