Video Experimental Relacionado

Updated: Apr 27, 2026

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

Acoplamiento oxidativo aeróbico catalizado por Pd de arenas: evidencia de transmesación entre dos intermediarios Pd

Dian Wang¹, Yusuke Izawa, Shannon S Stahl

¹Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.

Journal of the American Chemical Society

|June 27, 2014

Resumen

Este estudio revela que el acoplamiento oxidativo aeróbico catalizado por el paladio de arenas para formar biarilos procede a través de una vía bimetálica. Este mecanismo implica transmesación entre dos intermediarios de paladio (II) -arilo, apoyado por pruebas cinéticas e isotópicas.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
La catálisis de la catálisis.
Síntesis orgánica La síntesis orgánica.

Sus antecedentes:

El acoplamiento oxidativo aeróbico catalizado por paladio de arenas es un método clave para sintetizar compuestos biarílicos.
La formación de biarylo implica la activación de C-H y la eliminación reductora de C-C a través de un intermediario de paladio (II).
El mecanismo de formación del intermediario de paladio puede ser monometálico o bimetálico.

Objetivo del estudio:

Para dilucidar el mecanismo de acoplamiento oxidativo aeróbico catalizado por el paladio de o-xileno.
Para determinar si la reacción procede a través de una vía monometálica o bimetálica.
Para investigar el papel del sistema de catalizador PdX2/2-fluoropiridina.

Principales métodos:

Estudios cinéticos para determinar las velocidades de reacción en condiciones variables.
Experimentos de intercambio de hidrógeno-deuterio (H/D) para sondear la activación del enlace C-H.
Mediciones del efecto isotópico cinético (KIE) para evaluar el paso que determina la velocidad.

Principales resultados:

Se estudió la reacción del o-xileno con un catalizador PdX2/2-fluoropiridina.
Los datos cinéticos, el intercambio H/D y los KIEs apoyan fuertemente una vía de reacción específica.
La evidencia apunta hacia la formación del intermediario clave de paladio (II) a través de un mecanismo bimetálico.

Conclusiones:

El acoplamiento oxidativo aeróbico catalizado por el paladio del o-xileno sigue un mecanismo bimetálico.
La transmetalización entre dos intermedios de paladio ((II) -arilo es un paso crucial.
Esta visión mecanicista ayuda en el diseño racional de catalizadores para la síntesis de biarilo.

Más Videos Relacionados

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Published on: March 20, 2014

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

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...

Cycloaddition Reactions: Overview

Cycloaddition Reactions: Overview

Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.

Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction

Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction

The radical dimerization of ketones or aldehydes gives vicinal diols through a pinacol coupling reaction. However, the behavior of titanium metals used for the reaction as a source of electrons is unusual. When the reaction is carried out in the presence of titanium, diols can be isolated at low temperatures. Else titanium further reacts with diols, forming alkenes through the McMurry reaction.

Olefin Metathesis Polymerization: Overview

Olefin Metathesis Polymerization: Overview

Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.

Thermal and Photochemical Electrocyclic Reactions: Overview

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.