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La oxiaaminación asimétrica catalizada por el hierro de las olefinas
Kevin S Williamson1, Tehshik P Yoon
1Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Journal of the American Chemical Society
|July 17, 2012
Resumen
Un nuevo catalizador de hierro permite la oxiaaminación regioselectiva y enantioselectiva de alquenos, produciendo aminoalcoholes. Este método ofrece una regioquímica complementaria a los catalizadores de cobre, controlando la estereoquímica con metales baratos.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- La catálisis de la catálisis.
- Síntesis asimétrica de síntesis.
Sus antecedentes:
- La oximación de alquenos es crucial para la síntesis de valiosos compuestos que contienen nitrógeno.
- El desarrollo de métodos catalíticos eficientes y selectivos para la oxiaaminación sigue siendo un desafío importante en la síntesis orgánica.
Objetivo del estudio:
- Desarrollar un nuevo catalizador de hierro (II) para la oxiaaminación regioselectiva y enantioselectiva de alquenos.
- Explorar la regioselectividad complementaria de la reacción catalizada por hierro en comparación con los métodos catalizados por cobre existentes.
- Demostrar la utilidad de los productos de oxazolidina resultantes para acceder a los aminoalcoholes enantioenriquecidos.
Principales métodos:
- Utilizó un nuevo complejo de hierro (II) bis (oxazolina) como catalizador.
- Empleado N-sulfonilo oxaziridinas como la fuente de nitrógeno y oxígeno para la reacción de oxyamination.
- Investigó la regioselectividad y enantioselectividad del proceso catalítico.
- Manipuló los productos de oxazolidina para obtener aminoalcoholes libres.
Principales resultados:
- El catalizador de hierro (II) medió con éxito la oxiaaminación regioselectiva y enantioselectiva de los alquenos.
- La reacción produjo intermedios de oxazolidina que se convirtieron fácilmente en aminoalcoholes libres altamente enriquecidos con enantio.
- La regioselectividad observada con el catalizador de hierro fue complementaria a la de las reacciones catalizadas por cobre.
- Ambos regioisómeros de 1,2-aminoalcoholes enriquecidos con enantio podrían ser accedidos eligiendo entre catalizadores de hierro y cobre.
Conclusiones:
- Un nuevo catalizador de hierro (II) proporciona una ruta efectiva para la oxiaaminación asimétrica de alquenos.
- El proceso catalizado por hierro ofrece regioselectividad complementaria a la catálisis del cobre, permitiendo el acceso a diversos regioisómeros de aminoalcoholes.
- El uso de catalizadores de metales de transición de primera fila de bajo costo permite una regioquímica controlada en las reacciones de oxiaaminación mediadas por oxaziridina.
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