关闭了通往难以捉摸的4个成员环亚甲氨酸的机械路径
David F Dye1, Tillmann Köpke, Raghunath O Ramabhadran
1Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
Journal of the American Chemical Society
|July 2, 2011
概括
在低温下金属化的光解驱动了沃尔夫重组,形成亚基. 在室温反应中,从碳烯和烯中间体产生各种产品.
科学领域:
- 摄影化学的使用.
- 有机化学 有机化学
- 计算化学计算化学
背景情况:
- 研究金属化和自由基2-diazo-3-oxochlorins的光化学反应性.
- 了解二化合物的反应途径和中间体在有机合成中至关重要.
研究的目的:
- 为了研究金属化和自由基2-diazo-3-oxochlorins的低温光解.
- 阐明这些系统中沃尔夫重排的机制,并确定由此产生的光介质.
- 为了比较低温光化学与室温反应.
主要方法:
- 使用457.9nm激光在80K冷的多烯矩阵中进行光解.
- 电子吸收光谱的分析,以确定光介质.
- 红外吸收和拉曼光谱检测基和酸盐的振动.
- 计算建模包括振动光谱和TDDFT模拟.
- 产品分离和分析的反应在n-butanol-doped冷的多烯矩阵.
主要成果:
- 低温光解完全产生了一个单一的光介质,其光谱以低颜色转移.
- 红外和拉曼光谱证实了中间体的身份为基,表明了沃尔夫重排.
- 计算建模支持了沃尔夫重新排列机制和中间分配.
- 产品分析显示,在低温下几乎完全形成了亚二氨酸.
- 室温光解产生了来自碳和中间体的产品混合物.
结论:
- 沃尔夫对2-diazo-3-oxochlorins的重新排列在低温下是非常高效的,仅形成烯中间体,随后是azeteoporphyrins.
- 反应途径对温度敏感,室温有利于碳化合物形成.
- 冷矩阵和轨道对称性的几何约束有利于平面外的碳素,导致沃尔夫重排在80 K.
- 亚齐托波林的形成取决于基质的结构特征和反应条件.
相关概念视频
Amino Acid Biosynthetic Pathways
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which provide...
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.
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism
The Hofmann and Curtius rearrangement reactions can be applied to synthesize primary amines from carboxylic acid derivatives such as amides and acyl azides. In the Hofmann rearrangement, a primary amide undergoes deprotonation in the presence of a base, followed by halogenation to generate an N-haloamide. A second proton abstraction produces a stabilized anionic species, which rearranges to an isocyanate intermediate via an alkyl group migration from the carbonyl carbon to the neighboring...
Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
Five-Membered Heterocyclic Aromatic Compounds: Overview
Heterocyclic aromatic compounds are cyclic compounds that are aromatic and have one or more heteroatoms—atoms other than carbon, in the ring. Depending upon the number of atoms present in the ring, they can be either five or six-membered. Examples of five-membered heterocyclic aromatic compounds include pyrrole, furan, thiophene, and imidazole. Pyrrole consists of one nitrogen atom having one lone pair of electrons. Furan and thiophene have one oxygen and one sulfur heteroatom, respectively.

![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
