Reacciones enantio- y diastereoselectivas, estereospecíficas de tipo Mannich en el agua
Tomoaki Hamada1, Kei Manabe, Shu Kobayashi
1Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Journal of the American Chemical Society
|June 24, 2004
Resumen
Este estudio introduce un nuevo sistema catalítico utilizando fluoruro de zinc y una diamina quiral para reacciones asimétricas de tipo Mannich en el agua. El método logra altos rendimientos y estereospecificidad, produciendo aductos sin- o anti-Mannich.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Catalización asimétrica por catálisis asimétrica.
- Química verde es la química verde.
Sus antecedentes:
- Las reacciones asimétricas de tipo Mannich son cruciales para la síntesis de aminas quirales.
- Desarrollar sistemas catalíticos eficientes y selectivos en medios acuosos sigue siendo un desafío.
- El control estereoquímico en estas reacciones puede ser difícil de lograr.
Objetivo del estudio:
- Desarrollar un nuevo sistema catalítico para reacciones asimétricas de tipo Mannich en el agua.
- Para lograr altos rendimientos y selectividades utilizando catalizadores fácilmente disponibles.
- Para investigar la síntesis estereospecífica de syn y anti-Mannich aductos.
Principales métodos:
- Utilizó una combinación de fluoruro de zinc (ZnF2) y una diamina quiral con grupos metoxicos en anillos aromáticos.
- Reacciones catalíticas asimétricas de tipo Mannich realizadas en un entorno acuoso.
- Los enolados de silicio (E) o (Z) empleados como sustratos.
Principales resultados:
- Logró altos rendimientos y excelentes selectividades para las reacciones de tipo Mannich.
- Se ha demostrado la formación estereospecífica de adductos sin- o anti-Mannich.
- El sistema catalítico fue efectivo en el agua, alineándose con los principios de la química verde.
Conclusiones:
- El sistema catalítico desarrollado ofrece una ruta eficiente y selectiva para chiral Mannich añade en el agua.
- El resultado estereoquímico es controlable basado en la geometría del enolado de silicio.
- Este método proporciona una valiosa alternativa a las reacciones asimétricas de Mannich existentes.
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