Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Acidity of 1-Alkynes02:42

Acidity of 1-Alkynes

10.0K

The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
10.0K
Preparation of Acid Anhydrides01:07

Preparation of Acid Anhydrides

3.3K
One of the methods for preparing symmetrical or unsymmetrical acid anhydrides involves the treatment of acid chlorides with the sodium salt of carboxylic acids. The reaction proceeds via a nucleophilic acyl substitution.
The carboxylate ion acts as a nucleophile that attacks the carbonyl carbon of the acid chloride to form a tetrahedral intermediate. Subsequently, the re-formation of the carbonyl group with the loss of the chloride ion as a leaving group leads to the formation of an acid...
3.3K
Acid Halides to Carboxylic Acids: Hydrolysis01:01

Acid Halides to Carboxylic Acids: Hydrolysis

2.9K
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...
2.9K
α-Alkylation of Ketones via Enolate Ions01:10

α-Alkylation of Ketones via Enolate Ions

3.3K
Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the...
3.3K
Preparation and Reactions of Sulfides02:26

Preparation and Reactions of Sulfides

5.1K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
5.1K
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration02:34

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

8.6K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
8.6K

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

Effects of Cp*-Ligands in Titanocene-Based Thiosemicarbazone Complexes.

ACS omega·2026
Same author

Something germane about germanium: facile access to Ge<sub>10</sub> adamantane.

Chemical communications (Cambridge, England)·2026
Same author

Boragerma[5]pyramidanes via a Germole-to-Borole Rearrangement.

Inorganic chemistry·2026
Same author

Expanding the reactivity of Rosenthal's reagent to cyclopropenes and allenes.

Dalton transactions (Cambridge, England : 2003)·2026
Same author

Preyssler Polyoxometalate Supported Transition Metal Bipyridine Coordination Complexes.

Inorganic chemistry·2025
Same author

Fluctuating Behavior and Ligand-Dependent Reactivity of Isocyanates with Bis(pentafulvene)titanium Complexes.

Inorganic chemistry·2025

相关实验视频

Updated: Sep 9, 2025

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
09:45

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents

Published on: November 12, 2016

31.3K

化西利尔易斯酸的合理设计

Corinna Girschik1, Saskia Rathjen1, Lina Möllmann1

  • 1Institute of Chemistry, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Str. 9-11, Oldenburg, D-26129, Federal Republic of Germany, European Union.

Chemistry (Weinheim an der Bergstrasse, Germany)
|September 3, 2025
PubMed
概括

研究人员使用纳二烯或阿纳二烯支架合成了新型的酸利斯酸. 这些化合物表现出可调的易斯酸度,其中一些超过了三 (pentafluorophenyl) (BCF) 的强度.

关键词:
易斯的酸性 易斯的酸性这是NMR的NMR.是一种.是一种.基酸 (silyl cation) 是一种基酸.

更多相关视频

Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy
07:49

Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy

Published on: February 20, 2020

9.3K
Highly 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
06:31

Highly 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

9.7K

相关实验视频

Last Updated: Sep 9, 2025

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
09:45

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents

Published on: November 12, 2016

31.3K
Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy
07:49

Characterizing Lewis Pairs Using Titration Coupled with In Situ Infrared Spectroscopy

Published on: February 20, 2020

9.3K
Highly 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
06:31

Highly 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

9.7K

科学领域:

  • 有机化学 有机化学
  • 易斯酸催化剂的使用
  • 超分子化学 超分子化学

背景情况:

  • 酸性西利易斯酸在催化过程中至关重要,但它们的酸度调节仍然是一个挑战.
  • 与捐赠组稳定中心是调节易斯酸度的关键.
  • 纳夫他林和阿塞纳夫他林支架为易斯酸设计提供独特的结构平台.

研究的目的:

  • 为了合成和表征新型塞拉尼尔稳定型阴离子西利尔易斯酸.
  • 为了研究结构修改对易斯酸强度的影响.
  • 评估p-fluorobenzonitrile (FBN) 方法用于评估易斯酸度的有效性.

主要方法:

  • 合成含有纳二烯或阿纳二烯骨干的西利尔易斯酸.
  • 使用p-fluorobenzonitrile (FBN) 复合方法评估易斯酸强度.
  • 通过X射线晶体学和核磁共振 (NMR) 光谱学进行结构性表征.

主要成果:

  • 一系列的塞拉尼尔稳定型阴离子西利尔易斯酸被成功合成.
  • 易斯酸度是可调节的,一些化合物显示的强度大于三 (pentafluorophenyl) (BCF).
  • 结构研究证实了五协调在一个阴离子FBN复合体.

结论:

  • 结构性修改显著影响着易斯酸的易斯酸.
  • FBN方法是量化易斯酸强度微妙差异的可靠工具.
  • 这些发现为设计高效的易斯酸催化剂开辟了道路.