可观察到的具有抗芳香性质的azacyclobutenone化物来自2-diazoacetyl-azaaromatics
Nanyan Fu1, Annette D Allen, Shinjiro Kobayashi
1Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
Journal of the American Chemical Society
|April 25, 2007
概括
通过激光闪光光电解产生了新的azacyclobutenone ylides并使用激光闪光光电解进行了表征. 这些新型化合物在四个环中表现出显著的抗芳香性质,在六个环中表现出减少的芳香性.
科学领域:
- 有机化学 有机化学
- 摄影化学的使用.
- 物理化学 物理化学
背景情况:
- 阿扎西克洛布丁基化物是反应性中间体.
- 它们的生成和表征对于理解新化学结构至关重要.
研究的目的:
- 为了生成和描述新型的阿扎西克洛布丁基化物.
- 为了研究这些化物的电子和芳香性质.
主要方法:
- 激光闪光光解二甲和二甲二酸衍生物的激光光解.
- 使用IR和UV-Vis光谱的光谱识别.
- 核磁共振 (NMR) 光谱学和计算NICS计算.
主要成果:
- 成功生成并识别了阿扎西克洛布丁二化物2,11,14,17,19和21.
- 具有明显的红外和紫外线光谱的特点,超过21显示显著的持久性.
- 计算的NICS值和观察到的键交替表明四个环的抗芳香性强,六个环的芳香性降低.
结论:
- 这项研究表明,成功生成了新型阿扎西克洛布丁酸.
- 这些化物具有独特的电子特性,表明它们具有反芳香性质.
- 这些发现有助于理解循环有机化合物的芳香度和电子结构.
相关概念视频
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.
Aromatic Compounds: Overview
In general, the term ‘aromatic’ indicates a pleasant smell or fragrance from fresh flowers, freshly prepared coffee, etc. In the early history of organic chemistry, many benzene derivatives were isolated from the pleasant odor oils of the plants. For example, vanillin was isolated from the oil of vanilla, methyl salicylate from the oil of wintergreen, and cinnamaldehyde from the oil of cinnamon. They all had a pleasant odor; hence the name aromatic was given.
In 1825, Faraday isolated benzene...
In 1825, Faraday isolated benzene...
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo, or cyano...
Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
Nomenclature of Aryl and Heterocyclic Amines
The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.


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