Video Experimental Relacionado
Updated: Dec 3, 2025
10:10
Application of Elemental Lanthanides in the Selective C-F Activation of Trifluoromethylated Benzofulvenes Providing Access to Various Difluoroalkenes
Published on: July 28, 2018
6.7K
Escisión de enlaces C-F en trifluorometileranos utilizando un complejo de níquel bis-NHC
Hiroaki Iwamoto1, Hiroto Imiya1, Masato Ohashi2
1Department of Applied Chemistry, Osaka University, Suita, Osaka 565-0871, Japan.
Journal of the American Chemical Society
|October 28, 2020
Resumen
Este estudio demuestra por primera vez que los complejos de níquel pueden escindir el enlace C sp 3 F en los trifluorometilarenos. Esta reactividad permite un nuevo método de hidrodefluoración catalítica para estos compuestos difíciles.
Área de la Ciencia:
- Química organometálica
- Química del fluor
- Catálisis
Sus antecedentes:
- Los trifluorometilarenos son importantes intermediarios sintéticos.
- La activación de fuertes enlaces carbono-fluoro sigue siendo un desafío importante en la química.
- La catálisis del níquel ofrece una vía prometedora para la funcionalización de los enlaces C-F.
Objetivo del estudio:
- Indicar la primera adición oxidativa de un enlace C ((sp3) -F en los trifluorometileranos a un complejo de níquel ((0).
- Desarrollar una hidrodefluoración catalítica de los trifluorometilarenos.
- Para aclarar el mecanismo de la escisión del enlace C ((sp3) -F.
Principales métodos:
- Reacción de los trifluorometilarenos con un complejo de níquel que contiene ligandos de carbenos heterocíclicos N (NHC).
- Aislamiento y caracterización de los fluoros intermedios del níquel.
- Desarrollo de un protocolo de hidrodefluoración catalítica con el uso de hidrosilanos.
- Estudios computacionales para investigar el mecanismo de reacción.
Principales resultados:
- Un complejo de níquel con ligandos NHC estéricamente exigentes rompió con éxito el enlace C sp 3-F de los trifluorometilarenos.
- Se observó la formación de complejos de fluoruro de níquel-difluorobenzilo.
- Se logró una hidrodefluoración catalítica de los trifluorometilarenos utilizando hidrosilanos.
- El análisis computacional sugirió un mecanismo syn-SN2' para la escisión del enlace C ((sp3) -F.
Conclusiones:
- El estudio presenta un nuevo método para activar los enlaces C ((sp3) -F en los trifluorometilarenos mediante la catálisis del níquel.
- La reacción de hidrofluoración desarrollada ofrece una nueva vía sintética para acceder a valiosos compuestos fluorados.
- Los hallazgos proporcionan información mecanicista sobre la activación del enlace C-F mediada por níquel.
Videos de Conceptos Relacionados
01:26Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
2.1K
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
2.1K
01:13Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
7.1K
Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
7.1K
01:18Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
2.5K
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
2.5K
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
8.7K
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.
8.7K
01:11Nucleophilic Aromatic Substitution: Elimination–Addition
4.6K
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...
4.6K
02:50Catalysis
29.5K
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.
29.5K