Video Experimental Relacionado
Updated: Nov 11, 2025
07:06
A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
8.4K
Arilación deshidroximetilativa fotocatalítica por catálisis sinérgica de cerio y níquel
Yuegang Chen1, Xin Wang1, Xu He1
1School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
Journal of the American Chemical Society
|March 23, 2021
Resumen
Los alcoholes libres son ahora nucleófilos efectivos en acoplamientos cruzados C ((sp3) - C ((sp2)) utilizando catalizadores de cerio y níquel. Este nuevo método simplifica la construcción de enlaces entre alcoholes y haluros de arilo, extrudiendo formaldehído.
Área de la Ciencia:
- Química orgánica
- Catálisis
- Metodología sintética
Sus antecedentes:
- El desarrollo de métodos eficientes para la formación de enlaces C ((sp3) - C ((sp2)) es crucial en la síntesis orgánica.
- El uso de materiales de partida fácilmente disponibles y baratos como los alcoholes libres sigue siendo un desafío en las reacciones de acoplamiento cruzado.
Objetivo del estudio:
- Establecer un método nuevo y robusto para las reacciones selectivas de acoplamiento cruzado C ((sp3) - C ((sp2).
- Para permitir el uso de alcoholes libres como pronucleófilos en el acoplamiento cruzado con haluros de arilo.
- Introducir un nuevo paradigma para la construcción de enlaces C ((sp3) - C ((sp2)) con extrusión de formaldehído.
Principales métodos:
- El uso de catalizadores de cerio y níquel de bajo costo en condiciones de reacción suaves.
- Utilizando la experimentación automatizada de alto rendimiento para identificar ligandos efectivos.
- Desarrollo de ligandos de benzoato estérico para complejos de cerio.
Principales resultados:
- Demostró la utilidad de los alcoholes libres como pronucleófilos de carbono operacionalmente simples y robustos.
- Se obtienen acoplamientos cruzados selectivos C ((sp3) - C ((sp2)) entre una amplia gama de alcoholes y haluros aromáticos.
- Se ha identificado una cooperación sinérgica de la catálisis del cerio en la catálisis de los metales.
- Caracterizó un complejo de cerio tribenzoato como un intermediario de reacción.
Conclusiones:
- Se ha presentado un nuevo método versátil para la construcción de enlaces C(sp3) -C(sp2) utilizando alcoholes libres.
- Destacó la eficacia de la catálisis del cerio y el níquel en esta transformación.
- La metodología desarrollada ofrece un enfoque simplificado y robusto para sintetizar moléculas complejas.
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
Videos de Conceptos Relacionados
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.6K
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...
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...
3.6K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
11.5K
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.
11.5K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
8.4K
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.
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.
8.4K
01:22Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
2.1K
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.
2.1K
02:50Catalysis
28.9K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
28.9K
03:08Hydroboration-Oxidation of Alkenes
9.8K
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.
9.8K