Video Experimental Relacionado

Updated: Jun 13, 2026

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

Sustitución alilica catalizada por níquel de los alquenos simples mediante la sustitución alilica catalizada por

Ryosuke Matsubara¹, Timothy F Jamison

¹Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

Journal of the American Chemical Society

|May 4, 2010

Resumen

Este estudio introduce una nueva reacción catalizada por níquel para la alilación directa de alquenos simples. Representa el primer método catalítico intermolecular para esta transformación, logrando altos rendimientos con baja carga de catalizador.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis de la catálisis.
Química organometálica Química orgánica de los metales.

Sus antecedentes:

La alilación directa de alquenos simples es un desafío.
Los métodos existentes a menudo requieren sustratos pre-funcionalizados o alquenos tensados.

Objetivo del estudio:

Desarrollar una nueva reacción de sustitución alilica intermolecular catalizada por níquel.
Para permitir la alilación directa de alquenos simples, no conjugados y no tensados.

Principales métodos:

Sustitución alilica intermolecular catalizada por el níquel. sustitución alilica intermolecular catalizada por el níquel.
Utilizando etileno y alfa olefinas como sustratos.

Principales resultados:

El primer proceso intermolecular catalítico para la alilación directa de alquenos simples.
Los altos rendimientos se logran con cargas de catalizador tan bajas como 2.5 mol % Ni.
Tiene éxito tanto en reacciones a escala de gramo como en reacciones a escala más pequeña.

Conclusiones:

Este trabajo proporciona un método eficiente y versátil para la alilación de alquenos.
La catálisis del níquel desarrollada abre nuevas vías para la formación de enlaces C-C.

Más Videos Relacionados

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species

Published on: August 16, 2018

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Published on: February 16, 2020

Videos de Conceptos Relacionados

Radical Substitution: Allylic Bromination

Radical Substitution: Allylic Bromination

In organic synthesis, the formation of products can be altered by changing the reaction conditions. For example, a dibromo addition product is formed when propene is treated with bromine at room temperature. In contrast, propene undergoes allylic substitution in non-polar solvents at high temperatures to give 3-bromopropene. In order to avoid the addition reaction, the bromine concentration must be kept as low as possible throughout the reaction. This can be achieved using N-bromosuccinimide...

Radical Substitution: Allylic Chlorination

Radical Substitution: Allylic Chlorination

Typically, when alkenes react with halogens at low temperatures, an addition reaction occurs. However, upon increasing the temperature or under reaction conditions that form radicals, providing a low but steady concentration of halogen radicals, allylic substitution reaction is favored. This is because allylic hydrogens are very reactive as the formed intermediate is resonance stabilized. For example, when propene is treated with chlorine in the gas phase at 400 °C, it undergoes allylic...

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.

Nucleophilic Aromatic Substitution: Elimination–Addition

Nucleophilic Aromatic Substitution: Elimination–Addition

Simple aryl halides do not react with nucleophiles. However, nucleophilic aromatic substitutions can be forced under certain conditions, such as high temperatures or strong bases. The mechanism of substitution under such conditions involves the highly unstable and reactive benzyne intermediate. Benzyne contains equivalent carbon centers at both ends of the triple bond, each of which is equally susceptible to nucleophilic attack. This 50–50 distribution of products is confirmed through isotopic...

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...

Reactions of α-Halocarbonyl Compounds: Nucleophilic Substitution

Reactions of α-Halocarbonyl Compounds: Nucleophilic Substitution

Nucleophilic substitution in α-halocarbonyl compounds can be achieved via an SN2 pathway. The reaction in α-haloketones is generally carried out with less basic nucleophiles. The use of strong basic nucleophiles leads to the generation of α-haloenolate ions, which often participate in other side reactions.