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Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
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Una isomerización bioinspirada y catalítica de las olefinas activadas
Jan B Metternich1, Ryan Gilmour1
1Institute for Organic Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany.
Journal of the American Chemical Society
|August 28, 2015
Resumen
Los investigadores desarrollaron un método catalítico utilizando (-) -riboflavina para lograr una isomerización (Z) altamente selectiva de las olefinas activadas, un paso clave en la síntesis de compuestos valiosos como las cumarinas.
Área de la Ciencia:
- Química orgánica
- La fotoquímica
- Catálisis
Sus antecedentes:
- La naturaleza utiliza las flavinas para activar los polienos complejos.
- Los sistemas naturales a menudo exhiben una isomerización de Z a E.
Objetivo del estudio:
- Para traducir la activación mediada por flavina a un sistema de moléculas pequeñas.
- Para lograr una isomerización catalítica altamente (Z) selectiva de las olefinas activadas.
- Para invertir la direccionalidad de isomerización observada en los sistemas naturales.
Principales métodos:
- Se utiliza la (-) riboflavina como catalizador para la isomerización de las olefinas.
- Escafios de sustrato modificados mediante truncamiento y adición de sustitutos para inducir la deformación.
- Investiga la eficiencia de la reacción, los efectos aditivos y las sondas mecanicistas.
Principales resultados:
- Se logra una alta selectividad (Z) en la isomerización de las olefinas (hasta 99:1 Z/E).
- Invirtió con éxito la direccionalidad de isomerización a E → Z.
- Se ha demostrado la aplicabilidad del protocolo a los sustratos derivados de enonas y a la síntesis de cumarina.
- Identificamos un mecanismo de transferencia de energía triple.
Conclusiones:
- Desarrolló un protocolo de isomerización catalítica operacionalmente simple y altamente selectivo (Z).
- Estableció un paradigma de molécula pequeña para la activación de la olefina mediada por flavina.
- Mostró el potencial para sintetizar andamios médicamente relevantes como las cumarinas.
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