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Hidrogenación asimétrica altamente selectiva utilizando un catalizador de bisfosfina rodio de tres cuadrantes
Garrett Hoge1, He-Ping Wu, William S Kissel
1Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, Michigan 48105, USA. garrett.hoge@pfizer.com
Journal of the American Chemical Society
|May 13, 2004
Resumen
Un nuevo catalizador de rodio (5) permite la hidrogenación asimétrica altamente enantioselectiva de derivados de aminoácidos y precursores farmacéuticos. Este método ofrece ventajas para la síntesis a gran escala en comparación con los catalizadores existentes.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Catalización asimétrica por catálisis asimétrica.
- Química Medicinal La Química Medicinal es el campo de la Química Medicinal.
Sus antecedentes:
- Los ligandos quirales y los complejos metálicos son cruciales para la síntesis enantioselectiva.
- Los catalizadores de rodio son ampliamente utilizados en reacciones asimétricas de hidrogenación.
- La síntesis eficiente de compuestos enantioméricamente puros es vital para los productos farmacéuticos.
Objetivo del estudio:
- Para sintetizar ambos enantiómeros de un nuevo complejo de rodio (5).
- Para evaluar la enantioselectividad del complejo de rodio 5 en hidrogenación asimétrica.
- Para comparar la eficacia del catalizador 5a con Rh-Me-DuPhos para la síntesis a gran escala.
Principales métodos:
- Síntesis del ligando 2 y el complejo de rodio 5.
- Cromatografía líquida de alto rendimiento quiral (HPLC) para la separación enantiomérica.
- Hidrogenación asimétrica de los ácidos alfa-acetamido deshidroamino (6a-e) y el precursor de la pregabalina (8).
Principales resultados:
- Síntesis exitosa de ambos enantiómeros del ligando 2 y del complejo de rodio 5.
- El complejo de rodio 5 demostró una alta enantioselectividad (>99% ee) en las reacciones de hidrogenación.
- El catalizador 5a mostró ventajas sobre el Rh-Me-DuPhos para la hidrogenación a gran escala del precursor 8.
Conclusiones:
- El nuevo complejo de rodio 5, con cuadrantes obstaculizados, logra una excelente enantioselectividad.
- Este catalizador es eficaz para la hidrogenación asimétrica de derivados de aminoácidos y precursores farmacéuticos.
- El catalizador 5a presenta una alternativa prometedora para la hidrogenación asimétrica a escala industrial.
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