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Ciclopentanulación asimétrica C2-C3 del anillo indólico

José Barluenga¹, Eva Tudela, Alfredo Ballesteros

¹Instituto Universitario de Química Organometálica Enrique Moles, Unidad Asociada al C.S.I.C., Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.

Journal of the American Chemical Society

|January 30, 2009

Resumen

Los complejos de carbenos de tungsteno quiral (((0) facilitan una reacción de ciclización [3+2]. Este proceso sintetiza eficientemente el indol enantioméricamente puro y las ciclopentenonas fundidas de tetrahidropiridina y tetrahidropiridina.

Área de la Ciencia:

Química organometálica Química orgánica de los metales.
Síntesis orgánica La síntesis orgánica.
Catalización asimétrica por catálisis asimétrica.

Sus antecedentes:

Los complejos de carbenos quirales son valiosos intermediarios sintéticos.
El desarrollo de reacciones de ciclización enantioselectivas es crucial para la síntesis de moléculas complejas.

Objetivo del estudio:

Para investigar la [3+2] ciclización de los complejos quirales no racémicos alquinyl (((alcoxy) carbeno de tungsteno (((0).
Para sintetizar esqueletos de ciclopentenona fundidos enriquecidos enantioméricamente.

Principales métodos:

Se utilizan complejos quirales no racémicos de alquinila (alcoxi) carbeno de tungsteno (alcoxi) 0.
Se realizó una reacción de ciclización [3+2].
Los productos analizados para la pureza enantiomérica utilizando cromatografía quiral.

Principales resultados:

Se han sintetizado con éxito alfa-metilindoles y derivados de 1,6-dimetil-1,2,3,4-tetrahidropiridina.
Se logró la formación de esqueletos de ciclopentenona fusionada con 2,3-indolina y ciclopentenona fusionada con 2,3-piperidina.
Productos obtenidos con puridades enantioméricas muy altas, que oscilan entre el 96-99% ee.

Conclusiones:

Los complejos de carbenos de tungsteno quiral (((0) son catalizadores efectivos para las ciclizaciones [3+2] enantioselectivas.
Esta metodología proporciona una ruta directa a los sistemas de ciclopentenona fundida enantioméricamente pura.
El alto exceso enantiomérico demuestra la utilidad de este enfoque en la síntesis asimétrica.

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