Video Experimental Relacionado

Updated: Oct 21, 2025

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Published on: June 21, 2017

Hidroamidación de alquenos por medio de γ-C ((sp³) -H catalizada a distancia por NiH dirigida al tioéter por medio de

Bingnan Du¹, Yuxin Ouyang¹, Qishu Chen¹

¹State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.

Journal of the American Chemical Society

|September 8, 2021

Resumen

Este estudio introduce un método catalizado por hidróxido de níquel para la amidación remota de enlaces C-H de alquenos. El proceso logra altos rendimientos y regioselectividad dirigiendo la funcionalización al sitio de gamma-metileno.

Área de la Ciencia:

Química orgánica
Catálisis
Metodología sintética

Sus antecedentes:

La funcionalización del enlace C-H es un área clave en la química sintética.
El desarrollo de métodos para la funcionalización remota sigue siendo un desafío.
La catálisis de níquel ofrece una reactividad única para la activación de C-H.

Objetivo del estudio:

Desarrollar una nueva estrategia catalizada por níquel para la amidación remota de C-H.
Para permitir la funcionalización de alquenos no activados en la posición gamma-metileno.
Para lograr altos rendimientos y regioselectividad en el proceso de amidación.

Principales métodos:

La ciclometalización catalizada por el hidruro de níquel.
Activación remota de C-H dirigida por el tioéter.
Isomerización en cadena de los productos intermedios de níquel-hidruro.
Amidación con reactivos de dioxazolona.

Principales resultados:

Exitosa amidación remota de metileno C-H de alquenos no activados.
Se obtienen altos rendimientos (hasta el 90%) y una excelente selectividad regional (hasta 24:1 rr).
Demostró la utilidad del método con más de 40 ejemplos.
Se ha identificado la 2,9-dibutilo-1,10-fenantrolina (L4) como un ligando eficaz.

Conclusiones:

La estrategia desarrollada permite una amidación remota eficiente y selectiva por región.
La isomerización de caminata en cadena catalizada por níquel es crucial para la funcionalización selectiva del sitio.
Este método proporciona una herramienta valiosa para sintetizar moléculas complejas que contienen amida.

Más Videos Relacionados

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Published on: September 12, 2018

Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Published on: January 3, 2018

Videos de Conceptos Relacionados

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.

Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation

Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation

Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.

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.

Hydroboration-Oxidation of Alkenes

Hydroboration-Oxidation of Alkenes

In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.

Base-Promoted α-Halogenation of Aldehydes and Ketones

Base-Promoted α-Halogenation of Aldehydes and Ketones

α-Halogenation of aldehydes and ketones is a reaction involving the substitution of α hydrogens with halogens in the presence of a base. The reaction begins with the abstraction of α hydrogen by the base to produce a nucleophilic enolate ion. This intermediate undergoes a subsequent nucleophilic substitution with the halogen to produce a monohalogenated carbonyl compound. If the starting substrate has more than one α hydrogen, it is difficult to stop the reaction...

Acid-Catalyzed α-Halogenation of Aldehydes and Ketones

Acid-Catalyzed α-Halogenation of Aldehydes and Ketones

By replacing an α-hydrogen with a halogen, acid-catalyzed α-halogenation of aldehydes or ketones yields a monohalogenated product
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...