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Un estudio computacional DFT de la reacción de bisisilación del acetileno catalizado por complejos de paladio

Andrea Bottoni¹, Alicia Perez Higueruelo, Gian Pietro Miscione

¹Dipartimento di Chimica "G.Ciamician", Universita' di Bologna, via Selmi 2, 40126 Bologna, Italy. andrea@ciamserv.unibo.it

Journal of the American Chemical Society

|May 9, 2002

Resumen

Este estudio detalla la bisisilación catalizada por el paladio de los alquinos utilizando cálculos DFT ((B3LYP). El ciclo catalítico implica la adición oxidativa, la transferencia de grupos silílicos en varios pasos y la isomerización, que en última instancia forma (Z) -bis (silil) eteno.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
Química computacional es la química computacional.
La catálisis de la catálisis.

Sus antecedentes:

Los complejos de paladio son catalizadores cruciales en la síntesis orgánica.
La bisisilación de los alquinas ofrece una ruta a valiosos compuestos orgánicos que contienen silicio.
Comprender los mecanismos catalíticos es clave para optimizar la eficiencia de la reacción.

Objetivo del estudio:

Para dilucidar el detallado ciclo catalítico de la bisisilación de alquinos promovida por el paladio.
Para investigar el mecanismo de reacción utilizando la Teoría Funcional de Densidad (DFT) a nivel B3LYP.
Proporcionar información sobre la formación del (Z) -bis (sil) eteno. para proporcionar una visión de la formación de (Z) -bis (sil) eteno.

Principales métodos:

Cálculos de la Teoría Funcional de Densidad (DFT) utilizando el funcional B3LYP.
Modelado de un sistema catalítico con acetileno, disilano y un complejo de paladio (Pd(PH(3))(2)).
Análisis de vías de reacción, intermedios y barreras energéticas.

Principales resultados:

El ciclo catalítico comienza con la adición fácilmente oxidativa de disilano a Pd{\displaystyle Pd{\displaystyle Pd}
La transferencia del grupo silílico al alquino ocurre gradualmente, no de manera concertada, involucrando intermedios e isomerización.
La formación del producto (Z) -bis ((silil) eteno se favorece a través de vías de isomerización específicas.
El proceso catalítico general es exotérmico, liberando 41,54 kcal mol ((-1).

Conclusiones:

La investigación DFT (B3LYP) revela un mecanismo de varios pasos para la bisisilación catalizada por el paladio de los alquinos.
La isomerización de los intermediarios es crítica para la rápida formación del segundo enlace C-Si, lo que lleva al producto (Z) observado.
La exotermicidad global calculada se alinea bien con las observaciones experimentales, validando el mecanismo propuesto.

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