Video Experimental Relacionado

Updated: Jun 20, 2026

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Retropinacol/Cross-pinacol Coupling Reactions - A Catalytic Access to 1,2-Unsymmetrical Diols

Published on: April 4, 2014

Activación de cationes aromáticos de alcoholes: conversión a cloruros de alquilo mediante el uso de

Brendan D Kelly¹, Tristan H Lambert

¹Department of Chemistry, Columbia University, New York, New York 10027, USA.

Journal of the American Chemical Society

|September 12, 2009

Resumen

Este estudio introduce un nuevo método para activar los alcoholes utilizando éteres de ciclopropenio. Este nuevo enfoque convierte eficientemente varios alcoholes en cloruros de alquilo a través de una rápida reacción de desplazamiento nucleófilo.

Área de la Ciencia:

Química orgánica es la química orgánica.
Metodología sintética de la metodología sintética.

Sus antecedentes:

La activación del alcohol es crucial para las reacciones de sustitución nucleófila.
Los métodos existentes a menudo requieren condiciones duras o reactivos especializados.

Objetivo del estudio:

Desarrollar un método novedoso y eficiente para activar los alcoholes.
Para facilitar las reacciones de desplazamiento nucleófilo de alcoholes a través de intermediarios de éter de ciclopropenio.

Principales métodos:

Tratamiento de diversos sustratos alcohólicos con 3,3-dicloro-1,2-difenilciclopropeno.
Análisis de productos de reacción e intermedios utilizando la espectroscopia de resonancia magnética nuclear (RMN).
Estudios mecánicos, incluida la investigación de la vía S(N) 2 para el 1-fenilethanol.

Principales resultados:

Se estableció un nuevo paradigma para la activación del alcohol utilizando éteres de ciclopropenio.
Se logró una rápida conversión de varios alcoholes en los correspondientes cloruros de alquilo.
La evidencia de la espectroscopia de RMN (1) H apoyó la formación de un intermediario de ciclopropenio.
El mecanismo S(N) 2 fue confirmado como la vía primaria para el 1-fenilethanol.

Conclusiones:

El método descrito ofrece una ruta efectiva para la funcionalización del alcohol.
El uso de éteres de ciclopropenio proporciona una estrategia de activación suave y rápida.
La reacción demuestra un amplio alcance del sustrato con 12 ejemplos proporcionados.

Más Videos Relacionados

Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes

Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes

Published on: July 28, 2018

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Published on: November 21, 2017

Videos de Conceptos Relacionados

Halogenation of Alkenes

Halogenation of Alkenes

Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.

Electrophilic Aromatic Substitution: Friedel–Crafts Alkylation of Benzene

Electrophilic Aromatic Substitution: Friedel–Crafts Alkylation of Benzene

Friedel–Crafts reactions were developed in 1877 by the French chemist Charles Friedel and the American chemist James Crafts. Friedel–Crafts alkylation refers to the replacement of an aromatic proton with an alkyl group via electrophilic aromatic substitution. A Lewis acid catalyst such as aluminum chloride reacts with an alkyl halide to form a carbocation. The resulting carbocation then reacts with the aromatic ring and undergoes a series of electron rearrangements before giving the final...

Electrophilic Aromatic Substitution: Friedel–Crafts Acylation of Benzene

Electrophilic Aromatic Substitution: Friedel–Crafts Acylation of Benzene

The Friedel–Crafts acylation reactions involve the addition of an acyl group to an aromatic ring. These reactions proceed via electrophilic aromatic substitution by employing an acyl chloride and a Lewis acid catalyst such as aluminum chloride to form aryl ketone.

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

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...

Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids

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.

Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene

Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene

Chlorination and bromination are important classes of electrophilic aromatic substitutions, where benzene reacts with chlorine or bromine in the presence of a Lewis acid catalyst to give halogenated substitution products. A Lewis acid such as aluminium chloride or ferric chloride catalyzes the chlorination, and ferric bromide catalyzes the bromination reactions. During the bromination of alkenes, bromine polarizes and becomes electrophilic. However, in the bromination of benzene, the bromine...