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Memoria de la quiralidad axial en las fosfanilaciones del radical arilo
Achim Bruch1, Andrea Ambrosius, Roland Fröhlich
1Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 40, 48149 Münster, Germany.
Journal of the American Chemical Society
|July 30, 2010
Resumen
El Trimethylstannyl diphenylphosphane fosforila eficazmente los radicales arilo, manteniendo la quiralidad axial. Esta reacción produce fosfanos quirales y derivados valiosos para la investigación de catálisis asimétrica.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química organometálica Química orgánica de los metales.
- Catalización asimétrica por catálisis asimétrica.
Sus antecedentes:
- Los radicales arilo son intermediarios clave en la síntesis orgánica.
- Los fosfanos quirales son ligandos importantes en la catálisis asimétrica.
- El desarrollo de métodos eficientes para la síntesis de fosfanos quirales es crucial.
Objetivo del estudio:
- Para medir la constante de velocidad para la fosforilación de los radicales de arilo.
- Para investigar el resultado estereoquímico de las reacciones de fosfanilación.
- Para explorar la síntesis de fosfanos quirales y sus derivados.
Principales métodos:
- Medición de la constante de velocidad para la fosfanilación mediante el uso de trimetilstannildifenilfosfano (Me(3) SnPPh(2)).
- Atrapación de radicales arilo derivados de los o-haloanilidos axialmente quirales.
- Oxidación de fosfanos a óxidos o sulfuros de fosfano para su análisis.
- Las fosfanilaciones dobles y la subsiguiente oxidación/sulfurización.
- El atrapamiento quimiodivergente de los diastereómeros.
Principales resultados:
- Se determinó que la constante de velocidad para la fosfanilación es aproximadamente 9 x 10 ((8) M ((-1) s ((-1).
- La quiralidad axial se mantuvo completamente durante la fosfanilación de los radicales de arilo.
- Se sintetizaron enantiómeros de sulfuros de óxido de difosfano mezclados.
- El atrapamiento quimiodivergente de los diastereómeros condujo a diferentes formaciones de productos basadas en las condiciones de reacción.
Conclusiones:
- El Trimethylstannyl diphenylphosphane es un reactivo eficaz para la fosforilación de radicales arilo con una alta fidelidad estereoquímica.
- Los métodos desarrollados permiten la síntesis de fosfanos, óxidos y sulfuros de triarilo quiral.
- Estos compuestos quirales tienen potencial como ligandos en la catálisis asimétrica.
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