Video Experimental Relacionado

Updated: Jul 17, 2025

[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

Orange Light-Driven C ((sp²) -C ((sp³) Acoplamiento cruzado a través de la espina prohibida Ir ((III) Catalización de

Katherine A Xie¹, Eva Bednarova¹, Candice L Joe²

¹Department of Chemistry, Columbia University, New York, New York 10027, United States.

Journal of the American Chemical Society

|August 29, 2023

Resumen

Los investigadores desarrollaron nuevos fotocatalizadores de Iridium para la excitación de espín prohibido (SFE) utilizando luz naranja. Estos catalizadores permiten desafiar la formación de enlaces C ((sp2) - C ((sp3)) a través de la catálisis doble níquel/fotorredóxido en condiciones suaves.

Área de la Ciencia:

Química organometálica
Fotocatálisis
Química orgánica sintética

Sus antecedentes:

La doble catálisis de níquel y fotorredóxido es una herramienta poderosa para la formación de enlaces C-C.
Los métodos existentes a menudo requieren fuentes de luz de alta energía.
El acceso a los enlaces C ((sp2) - C ((sp3) en condiciones suaves y de baja energía sigue siendo un desafío.

Objetivo del estudio:

Desarrollar nuevos fotocatalizadores de Iridium (III) con capacidad de excitación de espín prohibido (SFE).
Aplicar estos fotocatalizadores a la construcción desafiante de enlaces C ((sp2) - C ((sp3)) utilizando luz visible de baja energía.
Para demostrar la amplia utilidad sintética de este nuevo sistema de fotocatalizador.

Principales métodos:

Síntesis y caracterización de una biblioteca de complejos de Iridio.
Reacciones fotocatalíticas que utilizan la irradiación de luz naranja (595 nm).
Catalización doble níquel/fotorredóxido utilizando los fotocatalizadores desarrollados con iridio.

Principales resultados:

Los fotocatalizadores de Iridium (III) desarrollados se someten eficientemente a SFE bajo luz naranja.
Construcción exitosa de bonos sintéticamente valiosos C ((sp2) - C ((sp3)) anteriormente inaccesibles.
Utilidad demostrada en las reacciones de arilación desaminativa y de acoplamiento cruzado de trifluoroborato de alquilo de potasio.
Amplio alcance del sustrato para ambos paradigmas de acoplamiento en condiciones suaves.

Conclusiones:

Este trabajo introduce una nueva familia de fotocatalizadores de Iridium (III) para la catálisis dual impulsada por la luz de baja energía.
Los fotocatalizadores desarrollados permiten la formación eficiente de enlaces C ((sp2) - C ((sp3)) en condiciones suaves.
Este es el primer ejemplo de acoplamiento de C(sp2)-C(sp3) metálico fotorredóxido de baja energía.

Más Videos Relacionados

ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis

ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis

Published on: August 19, 2021

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization

Published on: November 29, 2018

Videos de Conceptos Relacionados

Photochemical Electrocyclic Reactions: Stereochemistry

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Cycloaddition Reactions: MO Requirements for Photochemical Activation

Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.

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.

Thermal Electrocyclic Reactions: Stereochemistry

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.

Cycloaddition Reactions: MO Requirements for Thermal Activation

Cycloaddition Reactions: MO Requirements for Thermal Activation

Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.

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.