Video Experimental Relacionado

Updated: May 11, 2026

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes

Published on: December 16, 2019

Completamente regioselectiva funcionalización directa C-H de los benzo[b]tiofenos utilizando un catalizador

Dan-Tam D Tang¹, Karl D Collins, Frank Glorius

¹Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany.

Journal of the American Chemical Society

|May 8, 2013

Resumen

Los investigadores lograron la primera arilación selectiva de C-H de los benzo[b]tiofenos utilizando la catálisis del paladio. Este nuevo método acopla eficientemente los benzo[b]tiofenos con cloruros de arilo bajo condiciones suaves y libres de ligandos.

Área de la Ciencia:

Química orgánica es la química orgánica.
La catálisis de la catálisis.
Química Heterocíclica La Química Heterocíclica es una de las más conocidas.

Sus antecedentes:

Los benzo[b]tiofenos son importantes compuestos heterocíclicos con diversas aplicaciones.
La funcionalización selectiva C-H ofrece rutas sintéticas eficientes, pero sigue siendo un desafío para ciertos sustratos.
La catálisis del paládio es una herramienta poderosa en la síntesis orgánica, sin embargo, su pleno potencial en la funcionalización de los benzo[b]tiofenos está poco explorado.

Objetivo del estudio:

Para informar la primera arilación C3 C-H completamente selectiva de los benzo[b]tiofenos.
Demostrar una nueva reactividad del paladio en este contexto.
Desarrollar un método práctico y eficiente para sintetizar benzo[b]tiofenos arilados.

Principales métodos:

Se utilizó un sistema catalítico dual libre de ligandos que comprende paladio heterogéneo sobre carbono (Pd/C) y cloruro de cobre (CuCl).
Utilizó cloruros de arilo fácilmente disponibles como socios de acoplamiento.
Reacciones realizadas en condiciones insensibles al aire y la humedad.

Principales resultados:

Logró la primera arilación C3 C-H completamente selectiva de los benzo[b]tiofenos.
Demostró el acoplamiento de benzo[b]tiofenos con cloruros de arilo con alta eficiencia y selectividad.
El sistema de reacción era operacionalmente simple y robusto, tolerando el aire y la humedad.

Conclusiones:

El método desarrollado proporciona una ruta valiosa y selectiva a benzo[b]tiofenos arilados.
El estudio pone de relieve la reactividad del paladio no explotada anteriormente.
Se discutieron más investigaciones mecanicistas sobre las especies catalíticas y la vía de reacción.

Más Videos Relacionados

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)

Published on: June 20, 2014

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Published on: July 30, 2017

Videos de Conceptos Relacionados

Nucleophilic Aromatic Substitution: Elimination–Addition

Nucleophilic 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...

Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene

Electrophilic 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.

Reactions at the Benzylic Position: Halogenation

Reactions at the Benzylic Position: Halogenation

Benzylic halogenation takes place under conditions that favor radical reactions such as heat, light, or a free radical initiator like peroxide.

Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation

Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation

Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...

Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism

Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism

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...

Directing and Steric Effects in Disubstituted Benzene Derivatives

Directing and Steric Effects in Disubstituted Benzene Derivatives

When disubstituted benzenes undergo electrophilic substitution, the product distribution depends on the directing effect of both substituents. When the directing effects of both substituents reinforce each other, a single product is obtained. For example, bromination of p-nitrotoluene occurs ortho to the methyl group and meta to the nitro group, which is the same position, resulting in a single product. However, if the directing effects of the two groups oppose each other, the more strongly...