超分子"粉":一个六米的盐囊封装和功能化小分子碳化合物
Joseph M Marrett1,2, Hatem M Titi2, Yong Teoh2
1School of Chemistry, University of Birmingham Edgbaston Birmingham B15 2TT UK t.friscic@bham.ac.uk.
Chemical science
|December 22, 2023
概括
研究人员开发了一种超分子,它封装了固态维蒂格精反应的分子. 这种宿主-客人系统能够实现高效的机械化学转换,为化学合成提供了一种新的方法.
科学领域:
- 超分子化学 超分子化学
- 有机合成 有机合成
- 材料科学 材料科学 材料科学
背景情况:
- 维蒂格化是形成碳-碳双键的基本有机反应.
- 控制固态中的反应性仍然是化学合成的一个重大挑战.
- 超分子化学提供了组织分子和指导化学反应的工具.
研究的目的:
- 设计和合成一种新的六边形超分子子,用于封装小极分子.
- 为了证明这种宿主-客客系统对于固态机械化学维蒂格精的实用性.
- 建立超分子控制的固态反应的原理证明.
主要方法:
- 从Wittig类型的盐中组装一个六米级超分子子,使用电荷辅助素键.
- 在超分子内封装小极分子 (化物,) .
- 在固态宿主-客体复合体内,维蒂格精的机械化学激活.
- 随后的Sonogashira型合在现场生成的乙烯基胺替代物.
主要成果:
- 一个稳定的六极分子超分子子被成功合成和表征.
- 子证明了在预先制定的固体测量中对和的可靠封装.
- 实现了固态机械化学维蒂格精,转化了封装的客人.
- 主客复合体在随后的Sonogashira合中充当了乙烯基化物产品的替代品,使得单一的化物转化为enediyne.
结论:
- 一个新的超分子设计使固态反应成为可能,其中宿主也充当试剂.
- 这种方法为使用预制组件进行机械化学合成提供了一个新的平台.
- 开发的宿主-客户系统为固态中受控的有机转化提供了一种多功能策略.
相关概念视频
02:10Carbocations
11.3K
Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...
11.3K
01:14α-Halogenation of Carboxylic Acid Derivatives: Overview
3.3K
Unlike aldehydes and ketones, carboxylic acids do not readily participate in α halogenation reactions via enols or enolate intermediates. However, α-halogenated acids are obtained through other methods. One of the approaches is the Hell–Volhard–Zelinsky (HVZ) reaction, wherein the carboxylic acid is treated with halogen in the presence of PBr3. It involves the conversion of acid to acid halide, which exists in equilibrium with its enol form. The enol attacks the...
3.3K
02:38Electrophilic Addition to Alkynes: Halogenation
8.2K
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
8.2K
01:28Multiple Halogenation of Methyl Ketones: Haloform Reaction
2.0K
A method involving the transformation of methyl ketones to carboxylic acids using excess base and halogen is called the haloform reaction. It begins with the deprotonation of α hydrogen to form an enolate ion which reacts with the electrophilic halogen to give an α-halo ketone. The step continues until all the α protons are substituted to form a trihalomethyl ketone. The resulting molecule is unstable, and in the presence of a hydroxide base, it readily undergoes nucleophilic...
2.0K
01:01Acid Halides to Carboxylic Acids: Hydrolysis
2.6K
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
2.6K
01:15α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
3.0K
The method to achieve α-brominated carboxylic acids using a mixture of phosphorus tribromide and bromine is known as the Hell–Volhard–Zelinski reaction. The reaction is catalyzed by phosphorus tribromide, which can be used directly or produced in situ from red phosphorus and bromine. The mechanism comprises PBr3 catalyzed conversion of acid to acid bromide and hydrogen bromide. The acid bromide enolizes to its enol form in the presence of HBr. The nucleophilic enol attacks the...
3.0K