Search research articles

ACERCA DE JoVE

Visión General Liderazgo Blog Centro de Ayuda JoVE

AUTORES

Proceso de Publicación Consejo Editorial Alcance y Políticas Revisión por Pares Preguntas Frecuentes Enviar

BIBLIOTECARIOS

Testimonios Suscripciones Acceso Recursos Consejo Asesor de Bibliotecas Preguntas Frecuentes

INVESTIGACIÓN

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archivo

EDUCACIÓN

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Centro de Recursos para Profesores Sitio de Profesores

Términos y Condiciones de Uso

Política de Privacidad

Videos de Conceptos Relacionados

Stability of Substituted Cyclohexanes

Stability of Substituted Cyclohexanes

This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the...

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview

In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines.

Radical Reactivity: Steric Effects

Radical Reactivity: Steric Effects

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...

[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement

[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement

The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.

E1 Reaction: Stereochemistry and Regiochemistry

E1 Reaction: Stereochemistry and Regiochemistry

One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.

También podría leer

Artículos Relacionados

Artículos vinculados a este trabajo por autores compartidos, revista y gráfico de citas.

Ordenar por

Same author

Charging Pyracylene: Steering Aromaticity and Reactivity of [12]Annulene by Substitution.

Journal of the American Chemical Society·2026

Same author

Post-Modification of Tripyrenylenes to Enantiopure π-Extended D<sub>3</sub>-Symmetric Propellers.

Chemistry (Weinheim an der Bergstrasse, Germany)·2026

Same author

Copper-Catalyzed Domino Strategy Construction of Fused Benzopyrroloazepinone through the Reaction of Allenyloximes and Arylboronic Acids.

Organic letters·2026

Same author

Palladium-Catalyzed Approach to Highly Luminescent <i>para</i>-Difuropyrazines.

The Journal of organic chemistry·2026

Same author

Synthesis of Soft Octahedral Nanoparticles through Supramolecular Self-Assembly of <i>C</i><sub>3</sub>-Symmetric Trinaphthylamine Trisamides.

Journal of the American Chemical Society·2026

Same author

Toward Larger Cyclo-9,10-Anthryleneparaphenylenes.

Chemistry (Weinheim an der Bergstrasse, Germany)·2026

Same journal

A Ni-Mediated Cross-Coupling Approach to Deuterated <sup>18</sup>F- Fluoromethylated (Hetero)arenes.

Journal of the American Chemical Society·2026

Same journal

Efficient Light-Driven CO<sub>2</sub> Capture and Reversible Release Enabled by Metastable Photoacid-Decorated Metal-Organic Frameworks.

Journal of the American Chemical Society·2026

Same journal

In Situ Raman Spectroscopy Reveals the Dynamic Evolution and Ethanol Dependence of SEI Structure in Li-Mediated N<sub>2</sub> Reduction Reaction.

Journal of the American Chemical Society·2026

Same journal

Solvent Esterification and Stoichiometric Control in Ambient-Grown FAPbI<sub>3</sub> Single-Crystal Solar Cells.

Journal of the American Chemical Society·2026

Same journal

Unlocking Azulene Functionalization via Strain-Induced Azulyne Intermediates.

Journal of the American Chemical Society·2026

Same journal

An Oxazine-Locked Covalent Organic Framework by a Tandem Pinner/Schiff Base Reaction for Hydrogen Peroxide Photosynthesis.

Journal of the American Chemical Society·2026

Ver todos los artículos relacionados

Search research articles

Video Experimental Relacionado

Updated: Jul 2, 2025

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

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

Published on: August 22, 2018

Estabilización de los azaheptacenos

Wansheng Zong¹, Nikolai Hippchen¹, Nico Zeitter¹

¹Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.

Journal of the American Chemical Society

|February 27, 2024

Resumen

Este resumen es generado por máquina.

Este estudio sintetizó un derivado estable de diazaheptaceno mediante catálisis de paladio. Los voluminosos grupos TIPS-etinile y el núcleo de pirazina evitan la degradación, lo que permite su uso en transistores de película delgada.

Más Videos Relacionados

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Published on: July 28, 2022

Videos de Experimentos Relacionados

Last Updated: Jul 2, 2025

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

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

Published on: August 22, 2018

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

Published on: July 28, 2022

Área de la Ciencia:

Química orgánica
Ciencias de los materiales
Química supramolecular

Sus antecedentes:

Los heptacenos son hidrocarburos aromáticos policíclicos de gran tamaño con aplicaciones electrónicas potenciales.
Su inestabilidad inherente, debido a la dimerización y la oxidación, limita su uso práctico.
El obstáculo estérico y la incorporación de heteroátomos son estrategias para mejorar la estabilidad.

Objetivo del estudio:

Para sintetizar y caracterizar un nuevo y estable derivado del diazaheptaceno.
Investigar el efecto del posicionamiento del sustituyente y la incorporación de heteroátomos en la estabilidad del heptaceno.
Evaluar el rendimiento del material sintetizado en la electrónica orgánica.

Principales métodos:

Reacción de acoplamiento cruzado catalizada por paladio entre antracenos sustituidos.
Difracción de rayos X de un solo cristal para el análisis estructural.
Fabricación y caracterización de los transistores de película delgada (TFT).

Principales resultados:

Se sintetizó con éxito un heptaceno simétrico 7,16-diaza-6,8,15,17-tetráquico.
Los grupos de triisopropilosiletinilo (TIPS-etininilo) adyacentes al anillo central suprimieron efectivamente la dimerización.
El anillo central de pirazina confería estabilidad oxidativa, y los TFT exhibían una movilidad de electrones (μn) de 0,042 cm2/V·s.
Los patrones de sustitución alternativos y el aumento del contenido de nitrógeno redujeron la estabilidad.

Conclusiones:

La colocación estratégica de gruesos grupos TIPS-etinile y la incorporación de un anillo de pirazina son efectivas para estabilizar los núcleos de heptaceno.
El derivado de diazaheptaceno sintetizado es prometedor para aplicaciones electrónicas orgánicas.
Las investigaciones adicionales sobre las relaciones estructura-propiedad pueden guiar el diseño de semiconductores orgánicos avanzados.