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

Radical Reactivity: Steric Effects01:10

Radical Reactivity: Steric Effects

1.9K
The presence of electron-donating, electron-withdrawing, or conjugating groups adjacent to a radical center, imparts electronic stabilization to the radicals. Examples of such electronically-stabilized radicals are triphenylmethyl, tetramethylpiperidine‐N‐oxide, and 2,2‐diphenyl‐1‐picrylhydrazyl. These radicals are remarkably stable and are known as persistent radicals. Some of the persistent radicals can even be isolated and purified.
Along with electronic...
1.9K
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical 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
1.8K
Catalysis02:50

Catalysis

27.0K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
27.0K
Radical Halogenation: Stereochemistry01:33

Radical Halogenation: Stereochemistry

3.7K
Stereochemistry is the study of the different spatial arrangements of atoms in a given molecule. The stereochemistry of radical halogenations can be understood from three different situations:
Halogenation to form a new chiral center:
3.7K
Valence Bond Theory02:42

Valence Bond Theory

8.6K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.6K
Radicals: Electronic Structure and Geometry01:07

Radicals: Electronic Structure and Geometry

4.1K
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
4.1K

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

EXPRESS: Glymphatic System Dysfunction and Neurological Disorders: From Mechanisms to Therapeutic Strategies.

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism·2026
Same author

Photochemical Ni-Catalyzed Cross-Coupling of Aryl Bromides with Hydrazides.

The Journal of organic chemistry·2026
Same author

Controlled Dimerization of Rhodium(I) Isocyanides Enables Photophysical Properties Beyond Mononuclear Complexes.

JACS Au·2026
Same author

Photoactive four-coordinate copper(I) complexes based on chelating diimine, diphosphine, and diisocyanide ligands with high excited-state energies.

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

Photoinduced Generation of Alkyl Radicals from Dihydroquinazolinones for Difunctionalization of [1.1.1]Propellane.

Organic letters·2026
Same author

Photoinduced Mn catalysis for efficient platform for C-heteroatom bond coupling of aryl halides.

Nature communications·2026

相关实验视频

Updated: Jul 9, 2025

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
09:12

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

9.3K

催化剂控制五等价立体中心.

Anton Budeev1, Jianyang Dong1, Daniel Häussinger1

  • 1Department of Chemistry, University of Basel, Basel, Switzerland.

Nature communications
|December 4, 2023
PubMed
概括
此摘要是机器生成的。

研究人员开发了一种新的催化剂来控制五等价立体中心,扩大化学合成的可能性. 这一突破允许精确控制复杂的分子配置,此前是催化剂的重大挑战.

更多相关视频

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
19:58

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Published on: July 30, 2017

9.7K
Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
09:45

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

Published on: March 20, 2017

10.4K

相关实验视频

Last Updated: Jul 9, 2025

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
09:12

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

9.3K
Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
19:58

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Published on: July 30, 2017

9.7K
Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
09:45

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

Published on: March 20, 2017

10.4K

科学领域:

  • 立体化学是一种立体化学.
  • 催化剂是一种催化剂.
  • 有机合成 有机合成

背景情况:

  • 使用各种催化方法,四价立体中心得到了良好的控制.
  • 控制具有扩大立体化学空间的五价立体中心一直是化学的一个持续挑战.

研究的目的:

  • 为了证明五值立体中心的催化控制.
  • 开发一种用于五价化合物的enantioselective和 diastereoselective合成的方法.

主要方法:

  • 设计和合成了一种双功能伊米诺酸基氨酸催化剂.
  • 催化剂用于涉及五价酸的反应,以实现立体控制.

主要成果:

  • 催化剂使二氧化二氧化类立体异构体具有高产率 (高达99%) 和选择性 (高达96:4 e.r.r.) 的反选择性和反选择性合成成为可能. 和99:1的持续时间. ) 的情况.
  • 实现了立体分离催化,允许选择性访问五价酸的不同立体异构体状态.

结论:

  • 对五等价立体中心的催化控制是可行的.
  • 这项工作显著扩大了可合成地址的立体化学空间,特别是在高价值主群物种中.