用AgNO2和TEMPO对单基和异基烯的高效和立体选择性化
Soham Maity1, Srimanta Manna, Sujoy Rana
1Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Journal of the American Chemical Society
|February 15, 2013
概括
这项研究引入了一种使用银化物和TEMPO从烯酸合成烯酸的新方法. 这种方法实现了高的区域和立体选择性,克服了以前方法的局限性.
科学领域:
- 有机化学 有机化学
- 合成化学 合成化学
背景情况:
- 亚烯是有价值的合成试剂.
- 传统的合成方法经常产生cis和trans同位素的混合物,限制了它们的实用性.
研究的目的:
- 开发一种区域和立体选择性方法,从烯酸中合成二烯酸.
- 为现有的合成路线提供一种高效的替代品.
主要方法:
- 使用的银化物 (AgNO2) 与TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) 结合使用.
- 采用一种反应途径,涉及基基的形成和随后的转化.
主要成果:
- 实现了多种类型的烯酸的区域和立体选择性化.
- 展示了一种新的合成方法,从烯酸开始生产烯酸.
结论:
- 开发的方法提供了一种高效和有选择的途径,以nitroolefins.
- 这种方法克服了与传统烯合成相关的立体选择性挑战.
相关概念视频
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
Electrophilic Aromatic Substitution: Nitration of Benzene
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
Nitriles to Ketones: Grignard Reaction
Organomagnesium halides, commonly known as Grignard reagents, convert nitriles to ketones and proceed through a nucleophilic acyl substitution. Nitriles react with a Grignard reagent, followed by an aqueous acid, to yield ketones. The reaction introduces a new carbon–carbon bond. The alkyl–magnesium bond in the Grignard reagent is highly polar, so the alkyl carbon develops a carbanionic character and acts as a nucleophile.
The mechanism begins with a nucleophilic attack by the Grignard reagent...
The mechanism begins with a nucleophilic attack by the Grignard reagent...
Nitrosation of Enols
The nitrosation reaction is one of the methods of preparing 1,2-diketones. The enol tautomer of the starting ketone reacts with sodium nitrite in hydrochloric acid, generating the 1,2-diketone after hydrolysis.


