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Direct Detection of the Acetate-forming Activity of the Enzyme Acetate Kinase
Published on: December 19, 2011
Reacción aza-Henry enantioselectiva catalítica con un amplio alcance de sustrato
Claudio Palomo1, Mikel Oiarbide, Antonio Laso
1Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco, Apdo. 1072, 20080 San Sebastián, Spain. qoppanic@sc.ehu.es
Journal of the American Chemical Society
|December 15, 2005
Resumen
Este estudio introduce una nueva reacción aza-Henry enantioselectiva para las azometinas. El método utiliza precursores fácilmente disponibles y catalizadores quirales para lograr altos rendimientos y selectividades para los aductos de aza-Henry.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Catalización asimétrica por catálisis asimétrica.
Sus antecedentes:
- Las azometinas son intermedios versátiles en la síntesis orgánica.
- La reacción aza-Henry es crucial para la formación de enlaces carbono-nitrógeno.
- Es muy deseable desarrollar métodos enantioselectivos para las azometinas.
Objetivo del estudio:
- Desarrollar una reacción aza-Henry general y altamente enantioselectiva para las azometinas derivadas de aldehídos enolizables.
- Para explorar la diastereoselectividad y la enantioselectividad de la reacción con nitroetano.
Principales métodos:
- Generación in situ de azometinas a partir de precursores accesibles.
- Reacción con nitrometano o nitroetano utilizando monohidrato de hidróxido de cesio y sales quirales cuaternarias de amonio (derivadas de la quinina y la cinconidina).
Principales resultados:
- Logró buenos rendimientos y selectividades muy altas para los aductos aza-Henry.
- Demostró el primer método aza-Henry enantioselectivo general para azometinas de aldehídos enolizables, con excesos enantioméricos superiores al 94%.
- Se obtienen altas diastereoselectividades (syn:anti hasta 95:5) y enantioselectividades (hasta 98% ee para syn) cuando se utiliza nitroetano.
Conclusiones:
- El método desarrollado es eficaz para sintetizar aductos de aza-Henry enriquecidos enantioméricamente.
- Este trabajo proporciona una herramienta valiosa para la síntesis asimétrica, particularmente para los compuestos que contienen nitrógeno.
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