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Una expediente anulación [4 + 2] catalizada por fosfina: síntesis de tetrahidropiridinas altamente funcionalizadas
Xue-Feng Zhu1, Jie Lan, Ohyun Kwon
1Department of Chemistry, University of California, Los Angeles, California 90095-1569, USA.
Journal of the American Chemical Society
|April 17, 2003
Resumen
Una nueva reacción de anulación catalizada por fosfina sintetiza de manera eficiente las tetrahidropiridinas sustituidas utilizando el 2-metil-2,3-butadienoato de etilo como un sintetizador de 1,4 dipolo. Este método ofrece excelentes rendimientos, regioselectividad y diastereoselectividad para diversos derivados de piridina.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química sintética de la química sintética.
- La catálisis de la catálisis.
Sus antecedentes:
- Los sintetones de 1,4-dipolo son bloques de construcción valiosos en la síntesis orgánica.
- Los andamios de tetrahidropiridina son frecuentes en productos farmacéuticos y productos naturales.
- El desarrollo de métodos catalíticos eficientes para la síntesis de heterociclos es crucial.
Objetivo del estudio:
- Desarrollar una nueva reacción de anulación [4 + 2] para la síntesis de tetrahidropiridina.
- Para utilizar el 2-metil-2,3-butadienoato de etilo como un nuevo synthon 1,4-dipolo.
- Explorar el alcance y la estereoselectividad de la anulación desarrollada.
Principales métodos:
- Reacción del 2-metil-2,3-butadienoato de etilo con las N-tosiliminas.
- Empleando un catalizador orgánico de fosfina para la anulación [4 + 2].
- Utilizando etilo sustituido 2- ((substituido-metilo) -2,3-butadienoatos para ampliar el alcance.
Principales resultados:
- Se lograron excelentes rendimientos y una regioselectividad completa para el etil 6-sustituido-1-(4-tosil) -1,2,5,6-tetrahidro-piridina-3-carboxilatos.
- La expansión del alcance de la reacción produjo etilo 2,6-cis-disubstituido-1-(4-tosilo)-1,2,5,6-tetrahidro-piridina-3-carboxilatos.
- Se observaron altas diastereoselectividades en la síntesis de productos disubstituidos.
Conclusiones:
- Se ha establecido una nueva y eficiente reacción de anulación catalizada por fosfina [4 + 2].
- El 2-metil-2,3-butadienoato de etilo sirve como un eficaz 1,4-dipolo sintón para la síntesis de tetrahidropiridina.
- La reacción proporciona una ruta versátil a las tetrahidropiridinas altamente sustituidas con estereoquímica controlada.
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