活性金属黄金作为直接甲氧化碳化剂
Bingjun Xu1, Robert J Madix, Cynthia M Friend
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Journal of the American Chemical Society
|November 1, 2011
概括
金属金催化低温碳化酒精和氨基,形成关键中间体,如甲氧化碳. 这种对环境无害的方法为生产有价值的合成化学品提供了一种节能替代方案.
科学领域:
- 催化剂是一种催化剂.
- 绿色化学 绿色化学
- 有机合成 有机合成
背景情况:
- 传统的碳化反应通常需要恶劣的条件或产生有毒的副产品.
- 开发节能且对环境无害的催化工艺是化学合成的一个关键目标.
研究的目的:
- 探索金属黄金在低温碳化反应中的催化潜力.
- 建立一种新的,可持续的合成甲氧化碳中间体和相关化合物的途径.
主要方法:
- 甲醇和其他酒精/氨基的蒸汽相碳化,使用金属金作为催化剂.
- 反应中间体和产品的表征,包括甲氧化碳基的形成.
- 研究反应条件,重点关注低温和避免有毒化学品.
主要成果:
- 金属黄金有效催化一氧化碳 (CO) 直接插入甲醇的OH键,在低温下形成甲氧化碳.
- 该过程具有选择性,适用于一系列的醇和醇,以及二次胺.
- 作为一个具体的例子,二甲基碳酸盐是一种有价值的合成剂,被有效合成.
结论:
- 金属黄金作为一个高效的催化剂,用于低温,蒸汽相碳化.
- 这一发现为生产关键合成化学品提供了一个独特的,节能且对环境无害的框架.
- 该方法避免使用或产生有毒物质,与绿色化学原则保持一致.
相关概念视频
Preparation of Carboxylic Acids: Carboxylation of Grignard Reagents
Carboxylic acids can be prepared by the carboxylation of Grignard reagents (RMgX). This method is convenient for converting alkyl (primary, secondary or tertiary), vinyl, benzyl, and aryl halides to carboxylic acids with one additional carbon than the starting RMgX.
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
Oxidations of Aldehydes and Ketones to Carboxylic Acids
Oxidation of aldehydes and ketones results in the formation of carboxylic acids. Aldehydes, bearing hydrogen next to the carbonyl group, are easily oxidized compared to ketones. This is because an aldehydic proton can easily be abstracted during oxidation.
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...
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.
Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
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.


