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Millifluidics for Chemical Synthesis and Time-resolved Mechanistic Studies
Published on: November 27, 2013
El oro (((I) - catalizado estereoselectiva olefina ciclopropanación de la olefina
Magnus J Johansson1, David J Gorin, Steven T Staben
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|December 22, 2005
Resumen
Un nuevo complejo de oro ((I) cataliza la ciclopropanación de las olefinas utilizando ésteres de propargilo. Este método produce de manera eficiente los ciclopropanos de vinilo con alta enantioselectividad y cis-selectividad.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Catalización asimétrica por catálisis asimétrica.
Sus antecedentes:
- Los complejos de oro ((I) son catalizadores efectivos para las reacciones de transferencia de carbenos.
- Los ésteres de propargilo pueden servir como precursores para el oro ((I) -carbenos.
Objetivo del estudio:
- Desarrollar una ciclopropanación catalizada por oro de las olefinas.
- Para lograr la síntesis enantioselectiva de vinilo ciclopropanos.
Principales métodos:
- Reacción de ciclopropanación catalizada por trifenilfosfina y oro.
- Utilizó ésteres de propargilo como precursores de oro y carbeno.
- Empleó un complejo DTBM-SEGPHOS gold (I) para la catálisis enantioselectiva.
Principales resultados:
- Se logró una ciclopropanación exitosa de las olefinas.
- El catalizador DTBM-SEGPHOS gold (I) permitió la síntesis enantioselectiva de vinilo ciclopropano.
- Se obtuvo un alto exceso enantiomérico (hasta el 94% ee) y cis-selectividad.
Conclusiones:
- Se estableció un nuevo y eficiente método de ciclopropanación catalizada por oro.
- El protocolo desarrollado proporciona acceso a valiosos derivados del vinilo ciclopropano.
- El ligando DTBM-SEGPHOS es crucial para lograr una alta estereoselectividad en esta transformación.
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