扭曲的内分子电荷转移状态添加到电子贫乏的烯酸中
Mauricio Bahena Garcia1, Manvendra Singh1, Elizabeth Miller1
1Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, United States.
The Journal of organic chemistry
|February 14, 2024
概括
富含电子的arylpyrrolinium盐与迈克尔受体发生光化学反应,形成新的C-C键. 这项研究模拟了反应,解释了它的低效率,并探索了产品的修改.
科学领域:
- 有机化学 有机化学
- 摄影化学的使用.
- 反应机制 反应机制
背景情况:
- 酸盐在紫外线下与迈克尔受体发生反应.
- 这种反应形成了两个C-C键,并将基质区域选择性地碎片化.
研究的目的:
- 介绍光化学反应的机械模型.
- 为了纠正以前错误分配的产品结构.
- 调查反应优化和随后的修改.
主要方法:
- 频谱学是一种光谱学.
- 计算分析 计算分析
- 不断流动的化学化学
主要成果:
- 由实验和计算数据支持的机械模型被开发出来.
- 光化学反应的低效被归因于来自扭曲的分子内电荷转移状态的竞争性光.
- 修正了以前错误分配的结构.
结论:
- 阐明了光化学反应机制.
- 连续流的设置为这种反应提供了实际的优势.
- 随后的反应使得新化学结构的合成成为可能.
相关概念视频
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.0K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.0K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.8K
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
5.8K
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
5.8K
02:24Introduction to Electrophilic Addition Reactions of Alkenes
7.9K
The double bond in a simple, unconjugated alkene is a region of high electron density that can act as a weak base or a nucleophile. The filled π orbital (HOMO) of the double bond can interact with the empty LUMO of an electrophile. A bonding interaction occurs when the electrophile attacks between the two carbons; the electrophile then accepts a pair of electrons from the π bond and undergoes addition across the double bond, yielding a single product.
Addition and elimination...
Addition and elimination...
7.9K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.3K
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.
2.3K
02:47Structure and Bonding of Alkenes
16.4K
Olefins, which are unsaturated hydrocarbons containing one or more carbon–carbon double bonds, are broadly divided into alkenes and cycloalkenes. The general chemical formula of an alkene is CnH2n.
Doubly bonded carbons are sp2 hybridized and have a trigonal planar geometry. The double bond is composed of a σ bond formed by the overlap of hybrid orbitals and a π bond produced by the lateral overlap of unhybridized 2p orbitals on both the carbons. Each carbon atom is...
Doubly bonded carbons are sp2 hybridized and have a trigonal planar geometry. The double bond is composed of a σ bond formed by the overlap of hybrid orbitals and a π bond produced by the lateral overlap of unhybridized 2p orbitals on both the carbons. Each carbon atom is...
16.4K