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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 21, 2014
P-Cirogenic diaminophosphine oxide: una nueva clase de ligandos quirales de fósforo para la catálisis asimétrica
Tetsuhiro Nemoto1, Takayoshi Matsumoto, Takamasa Masuda
1Graduate School of Pharmaceutical Sciences, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
Journal of the American Chemical Society
|March 25, 2004
Resumen
Se sintetizó un nuevo ligando de óxido de diaminofosfina P-quirogénico y se utilizó para la sustitución alilica asimétrica catalizada por paladio. Este método crea eficientemente centros de carbono cuaternario quiral con alto rendimiento y enantioselectividad.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Síntesis asimétrica de síntesis.
Sus antecedentes:
- Los centros de carbono cuaternario son motivos estructurales cruciales en muchos productos farmacéuticos y productos naturales.
- El desarrollo de métodos catalíticos eficientes para su síntesis enantioselectiva sigue siendo un desafío importante en la química orgánica.
Objetivo del estudio:
- Para sintetizar un nuevo ligando de óxido de diaminofosfina P-quirogénico.
- Para aplicar este ligando en la sustitución alilica asimétrica catalizada por paladio para la construcción de centros de carbono cuaternarios.
Principales métodos:
- Síntesis de un nuevo óxido de diaminofosfina P-quirogénico (ligando 8).
- Reacciones asimétricas de sustitución alilica catalizadas por paladio utilizando varios ésteres beta-ceto.
- Estudios mecanicistas que involucran la formación del complejo de paladio (complejo Pd 9).
Principales resultados:
- El ligando 8 sintetizado se aplicó con éxito en la sustitución alilica asimétrica catalizada por Pd.
- Se lograron altos rendimientos (hasta el 99%) y una excelente enantioselectividad (hasta el 94% ee) en la construcción de centros de carbono cuaternarios.
- Los estudios mecánicos revelaron que la especie activa es un complejo Pd con una proporción de 1:2 de paladio a ligando (Pd:8 = 1:2).
Conclusiones:
- Un nuevo ligando de óxido de diaminofosfina P-quirogénico permite una eficiente construcción catalítica enantioselectiva de centros de carbono cuaternarios.
- La metodología desarrollada ofrece una herramienta valiosa para sintetizar moléculas quirales complejas.
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