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Adición asimétrica catalítica directa de cianuro de alilo a las cetonas
Ryo Yazaki1, Naoya Kumagai, Masakatsu Shibasaki
1Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Journal of the American Chemical Society
|February 14, 2009
Resumen
Este estudio introduce un nuevo método catalítico para la adición asimétrica de cianuro de alilo a las cetonas. El proceso produce alcoholes terciarios ópticamente enriquecidos con nitriles insaturados de configuración Z, mostrando un amplio alcance de sustrato.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Síntesis asimétrica de síntesis.
Sus antecedentes:
- El desarrollo de métodos eficientes para crear alcoholes terciarios quirales es crucial en la síntesis orgánica.
- Las reacciones asimétricas de adición a compuestos carbonílicos son transformaciones clave para generar estereocentros.
- El cianuro de alilo es un bloque de construcción versátil, pero su adición asimétrica directa a las cetonas sigue siendo un reto.
Objetivo del estudio:
- Desarrollar una nueva adición catalítica asimétrica directa de cianuro de alilo a las cetonas.
- Para lograr la adición exclusiva de gamma y una alta enantioselectividad en el producto.
- Explorar el alcance del sustrato y la generalidad del sistema catalítico desarrollado.
Principales métodos:
- Se utilizó un sistema catalítico bimetálico: (R,R) -Ph-BPE/[Cu(CH3CN)4]ClO4/LiOAr.
- Se emplearon condiciones de transferencia de protones con catálisis bifuncional ácido de Lewis blando/base de Brønsted dura.
- Investigó la reacción con una variedad de cetonas aromáticas, heteroaromáticas y alifáticas.
Principales resultados:
- Se logró la exclusiva adición gamma de cianuro de alilo a las cetonas.
- Alcoholes terciarios enriquecidos ópticamente sintetizados que contienen nitriles insaturados alfa y beta de configuración Z.
- Se ha demostrado una amplia generalidad de sustratos, incluyendo cetonas aromáticas, heteroaromáticas y alifáticas.
Conclusiones:
- El sistema catalítico bimetálico desarrollado proporciona una ruta eficiente para la adición asimétrica gamma de cianuro de alilo.
- La reacción ofrece un método valioso para acceder a los alcoholes terciarios quirales con valiosas funcionalidades de nitrilo insaturado.
- La amplia aplicabilidad del método en sustratos destaca su potencial para diversas aplicaciones sintéticas.
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