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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
Un catalizador de fosfabicicloctano altamente enantioselectivo para la resolución cinética de los alcoholes
1Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA. edved@umich.edu
Journal of the American Chemical Society
|April 3, 2003
Resumen
Los investigadores desarrollaron nuevas fosfinas quirales (PBO) para una resolución cinética eficiente de los aril alquilo carbinolos. Estos catalizadores PBO logran altas enantioselectividades, lo que demuestra su potencial en la síntesis asimétrica.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Síntesis asimétrica de síntesis.
- La catálisis de la catálisis.
Sus antecedentes:
- Las fosfinas quirales son ligandos cruciales en la catálisis asimétrica.
- El desarrollo de catalizadores eficientes para la resolución cinética sigue siendo un desafío clave en la síntesis orgánica.
Objetivo del estudio:
- Para sintetizar una nueva clase de fosfinas quirales, los derivados del P-arilo-2-fosfabiciclo[3.3.0]octano (PBO).
- Evaluar la eficacia de estas fosfinas PBO como catalizadores para la resolución cinética de los aril alquilo carbinolos.
Principales métodos:
- Síntesis enantioselectiva de fosfinas PBO a partir de ésteres de lactato y 2,2-dimetilciclopentano enolado.
- Estrategias de alquilación selectiva de enolados y de ciclización diastereoselectiva.
- Resolución cinética de los alquilcarbinolos de arilo a través de la benzoilación o la iso-butiroilación.
Principales resultados:
- El éxito en la preparación de nuevas fosfinas quirales PBO.
- Se ha demostrado una alta actividad catalítica y enantioselectividad en resoluciones cinéticas.
- Se han logrado enantioselectividades superiores a 100 y un factor de selectividad de 380 +/- 10 para el metilmesitilcarbinol.
Conclusiones:
- Las fosfinas PBO recientemente sintetizadas son catalizadores efectivos para la resolución cinética de los aril-alquilo-carbinolos.
- El mecanismo catalítico probablemente involucra un intermediario de carboxilato de P-acilfosfonio con un estado de transición estrechamente emparejado con iones.
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