Video Experimental Relacionado
Updated: Jun 12, 2026
19:58
Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
La trifluorometilación catalizada por el paladio de los cloruros de arilo
Eun Jin Cho1, Todd D Senecal, Tom Kinzel
1Department of Chemistry, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
Science (New York, N.Y.)
|June 26, 2010
Resumen
Un nuevo método catalizado con paladio permite una leve trifluorometilación de cloruros de arilo. Este enfoque amplía el alcance de la introducción del grupo trifluorometilo en diversas moléculas orgánicas, incluidos los complejos intermedios farmacéuticos.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química Medicinal La Química Medicinal es un campo de estudio de la química medicinal.
- Ciencia de los materiales Ciencia de los materiales.
Sus antecedentes:
- El grupo trifluorometil mejora significativamente las propiedades moleculares, impactando los productos farmacéuticos, agroquímicos y materiales.
- Los métodos de trifluorometilación existentes a menudo implican condiciones adversas o una compatibilidad limitada del sustrato.
- Falta un método general y suave para instalar el grupo trifluorometilo en sustratos aromáticos funcionalizados.
Objetivo del estudio:
- Desarrollar un método general y suave catalizado con paladio para la trifluorometilación de cloruros de arilo.
- Para ampliar la utilidad sintética de los compuestos trifluorometilados.
- Para permitir la funcionalización en etapa tardía de moléculas orgánicas complejas.
Principales métodos:
- Reacción de acoplamiento cruzado catalizada por paladio.
- Trifluorometilación de cloruros de arilo utilizando un nuevo sistema catalítico.
- Caracterización de los intermediarios catalíticos.
Principales resultados:
- Trifluorometilación exitosa de una amplia gama de cloruros de arilo, incluidos los heterociclos, en condiciones suaves.
- Altos rendimientos logrados a través de diversos sustratos.
- Tolerancia demostrada de varios grupos funcionales (ésteres, amidas, éteres, acetales, nitriles, aminas terciarias).
- Preparación y validación de los principales intermediarios catalíticos.
Conclusiones:
- El método desarrollado ofrece una ruta versátil y eficiente para la trifluorometilación.
- El proceso es adecuado para la modificación en etapa tardía de intermedios farmacéuticos y agroquímicos avanzados.
- Este avance proporciona una herramienta valiosa para la síntesis orgánica y el descubrimiento de fármacos.
Más Videos Relacionados
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)
Videos de Conceptos Relacionados
01:13Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
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.
01:15Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
Chlorination and bromination are important classes of electrophilic aromatic substitutions, where benzene reacts with chlorine or bromine in the presence of a Lewis acid catalyst to give halogenated substitution products. A Lewis acid such as aluminium chloride or ferric chloride catalyzes the chlorination, and ferric bromide catalyzes the bromination reactions. During the bromination of alkenes, bromine polarizes and becomes electrophilic. However, in the bromination of benzene, the bromine...
01:11Electrophilic Aromatic Substitution: Friedel–Crafts Acylation of Benzene
The Friedel–Crafts acylation reactions involve the addition of an acyl group to an aromatic ring. These reactions proceed via electrophilic aromatic substitution by employing an acyl chloride and a Lewis acid catalyst such as aluminum chloride to form aryl ketone.
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
01:11Nucleophilic 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...
01:26Limitations of Friedel–Crafts Reactions
Several restrictions limit the use of Friedel–Crafts reactions. First, the halogen in the alkyl halide must be attached to an sp3-hybridized carbon for the Friedel–Crafts reactions to occur. Vinyl or aryl halides do not react since the carbocations formed are unstable under the reaction conditions. Second, Friedel–Crafts alkylation is susceptible to carbocation rearrangement, and the major products obtained have a rearranged carbon skeleton. In contrast, the acylium ion is stabilized by...