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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
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Sonogashira acoplamiento cruzado y homoacoplamiento en una superficie plateada: clorobenzeno y fenilacetileno en
Carlos Sanchez-Sanchez1, Noe Orozco, Juan P Holgado
1Instituto de Ciencia de Materiales de Sevilla (CSIC), Americo Vespucio 49, 41092 Seville, Spain.
Journal of the American Chemical Society
|December 23, 2014
Resumen
Las superficies plateadas facilitan las reacciones de acoplamiento de fenilacetileno y clorobenzeno. Este estudio explora una nueva catálisis heterogénea utilizando plata y el típicamente inerte clorobenceno, revelando información sobre la adsorción y la formación de islas que afectan la actividad química.
Área de la Ciencia:
- Ciencias de la superficie Ciencias de la superficie.
- Catálisis Heterogénea Catálisis Heterogénea
- Química orgánica es la química orgánica.
Sus antecedentes:
- La plata es un catalizador subutilizado para las reacciones de acoplamiento orgánico.
- El clorobenzeno generalmente se considera no reactivo en las reacciones de Sonogashira y homoacoplamiento.
- Comprender el comportamiento del adsorbado en las superficies metálicas es crucial para el diseño del catalizador.
Objetivo del estudio:
- Investigar la adsorción y reacción del fenilacetileno y el clorobenzeno en Ag100).
- Explorar el potencial de la plata como catalizador para Sonogashira y las reacciones de homoacoplamiento que involucran al clorobenzeno.
- Para aclarar el papel de las configuraciones de adsorción y la formación de islas en las vías de reacción.
Principales métodos:
- Microscopía de exploración de túnel (STM) para imágenes de superficie.
- Reacción programada por temperatura (TPR) para estudiar la cinética de la reacción.
- Espectroscopia de estructura fina de absorción de rayos X de borde cercano (NEXAFS) para el análisis de la estructura electrónica.
- Cálculos de la Teoría Funcional de Densidad (DFT) para las energías y configuraciones de adsorción.
Principales resultados:
- El fenilacetileno y el clorobenzeno se someten a un homoacoplamiento heterogéneo y a un acoplamiento cruzado de Sonogashira en Ag{100}.
- Ambas moléculas se adsorben en una conformación plana, principalmente a través de fuerzas de dispersión, lo que lleva a la activación química.
- Se observó la formación de islas para ambos adsorbados, lo que potencialmente limita la actividad química general y se produce en los límites de las islas.
Conclusiones:
- La plata es un catalizador viable e inexplorado para reacciones de acoplamiento que involucran fenilacetileno y clorobenzeno.
- Las propiedades de adsorción y la formación de islas influyen significativamente en el rendimiento catalítico de Ag{100}.
- Los hallazgos proporcionan una base para el desarrollo de sistemas catalíticos prácticos basados en plata para la síntesis orgánica.
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