相关概念视频
01:33Radical Reactivity: Intramolecular vs Intermolecular
1.7K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
1.7K
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
18.0K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
18.0K
01:16Cycloaddition Reactions: Overview
2.6K
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
2.6K
01:11Nucleophilic Aromatic Substitution: Elimination–Addition
4.0K
Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is...
4.0K
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
02:34Preparation of Alkynes: Dehydrohalogenation
15.7K
Introduction
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
15.7K
您也可能阅读
相关文章
通过共同作者、期刊和引用图与本文相关的文章。
排序
Same author
Pyridine C─N Transposition via Cycloaddition-Cycloreversion.
Angewandte Chemie (International ed. in English)·2026
Same author
All-metal aromaticity of cyclo-Bi<sub>3</sub><sup>3-</sup> in diuranium and dithorium inverse-sandwich-type complexes.
Nature chemistry·2026
对于分子内二甲基合成的XAT-催化.
Thomas Sephton1, Jonathan M Large2, Louise S Natrajan1
1School of Chemistry, University of Manchester, Manchester, M13 9PL, UK.
Angewandte Chemie (International ed. in English)
|May 31, 2024
概括
可见光光氧化催化使得通过激进的ipso-substitution有效的二甲基合成,避免苛刻的试剂. 这种方法促进了C-N键在线的直接结合.
更多相关视频
06:31Highly Stereoselective Synthesis of 1,6-Ketoesters Mediated by Ionic Liquids: A Three-component Reaction Enabling Rapid Access to a New Class of Low Molecular Weight Gelators
Published on: November 27, 2015
9.6K
10:44Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
10.8K
科学领域:
- 有机化学 有机化学
- 光催化作用的光催化
- 合成方法论 合成方法论
背景情况:
- 双化合物在制药和材料科学中至关重要.
- 传统的二甲基合成通常依赖于有机金属试剂,这些试剂可能是有毒的或需要固态量.
- 激进的ipso-substitution提供了一个替代方案,但往往需要严苛的条件或固体测量激进的发起者.
研究的目的:
- 开发一种新的,高效的,更温和的方法,用于使用可见光光电还原催化剂合成二.
- 探索 photoredox 条件下的极端ipso-substitution 的应用.
- 为了使惰性C-N键的直接结合,例如在anilines中的那些.
主要方法:
- 可见光光电还原催化.
- 原子转移 (XAT) 机制.原子转移 (XAT) 机制.
- 使用特定的胺基质直接进行ipso-substitution而不是ortho-addition.
主要成果:
- 通过光电氧催化性ipso-substitution成功合成了双化合物.
- 证明了与迁移的环的各种电子属性的兼容性.
- 实现了氨酸C-N键的单形式化.
结论:
- 可见光光氧化催化提供了一种强大而可持续的替代品,用于二合成.
- 开发的方法提供了广泛的基质范围和功能组耐受性.
- 这种方法为C-N债券功能化开辟了新的途径.