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Síntesis enantioconvergente de γ-butirolactonas funcionalizadas a través de la anulación (3 + 2)

C Guy Goodman¹, Morgan M Walker, Jeffrey S Johnson

¹Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.

Journal of the American Chemical Society

|December 24, 2014

Resumen

Este estudio introduce una resolución cinética dinámica para crear moléculas complejas. Una nueva reacción asimétrica genera eficientemente gamma-butirolactonas con tres estereocentros precisos.

Área de la Ciencia:

Química orgánica es la química orgánica.
Catalización asimétrica por catálisis asimétrica.
Síntesis estereoselectiva de síntesis.

Sus antecedentes:

La creación de moléculas con múltiples estereocentros es crucial en el descubrimiento de fármacos y la ciencia de los materiales.
Los métodos existentes para sintetizar gamma-butirolactonas con estereocentros contiguos a menudo se enfrentan a limitaciones en eficiencia y control.
La resolución cinética dinámica (DKR) ofrece una poderosa estrategia para maximizar el rendimiento del producto y la pureza estereocímica.

Objetivo del estudio:

Desarrollar una nueva reacción asimétrica para la resolución cinética dinámica de los ésteres beta-halo alfa-ceto.
Para lograr la formación de gamma-butirolactonas que poseen tres estereocentros contiguos con alto control.
Establecer un proceso de DKR intermolecular para una síntesis estereoselectiva eficiente.

Principales métodos:

Utilizó un catalizador quiral de carbenos N-heterocíclicos para mediar la reacción.
Empleado una estrategia de adición umpolung que involucra alfa, beta-enales y ésteres alfa-ceto racémicos.
Investigó la capacidad de la reacción para controlar la regioselectividad, la diastereoselectividad y la enantioselectividad.

Principales resultados:

Se realizó con éxito una resolución cinética dinámica de los ésteres beta-halo alfa-ceto.
Generó gamma-butirolactonas con tres estereocentros contiguos con alta regio-, diastereoselectividad y enantiocontrol.
Demostró la efectividad del proceso de DKR intermolecular en la fijación de múltiples estereocentros en un solo evento de formación de enlaces.

Conclusiones:

La metodología desarrollada proporciona una ruta eficiente a las gamma-butirolactonas complejas.
Esta reacción asimétrica de homoenolatos representa un avance significativo en la síntesis estereoselectiva.
El enfoque de DKR intermolecular ofrece una plataforma versátil para construir moléculas con múltiples estereocentros.

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