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La orto-sililación de arenos catalizados por iridio por activación formal C-H dirigida por hidroxilo
Eric M Simmons1, John F Hartwig
1Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA.
Journal of the American Chemical Society
|November 17, 2010
Resumen
Un nuevo método permite la orto-silición de compuestos aromáticos utilizando grupos hidroxilo como elementos de dirección para la activación C-H catalizada por iridio. Este proceso forma benzoxasiloles, que pueden convertirse en valiosos derivados de fenol o biarilo.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis por catálisis.
- Metodología sintética de la metodología sintética.
Sus antecedentes:
- La activación dirigida de C-H es una herramienta poderosa en la síntesis orgánica.
- Los grupos hidroxilo pueden actuar como elementos directores en reacciones catalizadas por metales.
- Los métodos eficientes para la orto-silición son cruciales para la construcción de moléculas complejas.
Objetivo del estudio:
- Desarrollar una nueva estrategia para la orto-silición de cetonas de arilo, benzaldehídos y alcoholes bencílicos.
- Para utilizar grupos hidroxilo como elementos de dirección para la activación de enlaces C-H catalizados por iridio.
- Para sintetizar los intermediarios de benzoxasiloles y demostrar su utilidad sintética.
Principales métodos:
- Generación de éteres (hidrido) silílicos de un solo bote a partir de compuestos o alcoholes carbonílicos.
- Ciclización deshidrogenativa catalizada por [Ir(cod) OMe]2 y 1,10-fenantrolina en presencia de norborneno.
- Oxidación Tamao-Fleming y acoplamiento cruzado Hiyama para la transformación de productos.
Principales resultados:
- El éxito de la orto-silición de varios sustratos aromáticos.
- Formación de derivados de benzoxasiloles a través de la activación y ciclización de C-H catalizada por Ir.
- Demostración de la utilidad sintética de los benzoxasiloles a través de la conversión a fenoles y biarilos.
Conclusiones:
- Se ha establecido una estrategia novedosa y eficiente para la orto-silición.
- La activación de C-H dirigida por hidroxilo proporciona una ruta versátil a las benzoxasilolas.
- El método desarrollado ofrece una valiosa vía para sintetizar compuestos aromáticos funcionalizados.
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