関連する実験動画

Updated: Sep 9, 2025

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
11:45

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Published on: August 22, 2018

8.5K

24π抗芳香サピリンと22π芳香ディケーションディマーを結びつけるβ-βの逆転環酸化

Hosahalli S Udaya1, Venkataramanarao G Anand1

  • 1Department of Chemistry, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India.

Organic letters
|September 3, 2025
PubMed
まとめ

研究者らは,最初のβ-β結合した抗芳香性膨張型ポルフィリノイド二酸化物を合成した. この新種の抗芳香化合物は 酸化時に独特の電子特性を発揮し 新しい材料への道を開きます

さらに関連する動画

Solid-phase Synthesis of [4.4] Spirocyclic Oximes05:15

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

Published on: February 6, 2019

6.9K
Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions04:38

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Published on: July 28, 2022

3.1K

関連する概念動画

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.3K
Thermal Electrocyclic Reactions: Stereochemistry01:17

Thermal Electrocyclic Reactions: Stereochemistry

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.
2.1K
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH301:11

ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
6.3K
Aromatic Hydrocarbon Anions: Structural Overview01:18

Aromatic Hydrocarbon Anions: Structural Overview

Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous...
2.9K
Electrophilic Aromatic Substitution: Overview01:16

Electrophilic Aromatic Substitution: Overview

In an electrophilic aromatic substitution reaction, an electrophile substitutes for a hydrogen of an aromatic compound.
11.5K
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids02:04

Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids

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.
6.1K