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Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

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Anulaciones controladas por catalizadores de alienos cíclicos tensados con complejos de π-alilpalladio

Dominick C Witkowski¹, Matthew S McVeigh¹, Georgia M Scherer¹

¹Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States.

Journal of the American Chemical Society

|May 4, 2023

Resumen

Este estudio presenta las primeras reacciones de anulación exitosas de alenos cíclicos tensados con paladio. Estas reacciones construyen rápidamente andamios policíclicos complejos, heterocíclicos y estereocímicamente ricos.

Área de la Ciencia:

Química orgánica
Química sintética
Catálisis

Sus antecedentes:

Los alenos cíclicos tensados son intermedios reactivos, conocidos desde hace más de 50 años.
Sus aplicaciones sintéticas, especialmente con la catálisis de metales de transición, siguen siendo poco exploradas.
Atrapar estos intermediarios fugaces es un desafío, pero ofrece vías a moléculas complejas.

Objetivo del estudio:

Para reportar la primera anulación de los alenos cíclicos tensados con paladio.
Demostrar la síntesis selectiva de andamios policíclicos utilizando estos productos intermedios.
Para expandir la utilidad de los alenos cíclicos tensados en la síntesis de moléculas complejas.

Principales métodos:

Generación in situ de allenos cíclicos altamente reactivos.
Reacciones de anulación con especies de π-alipaládio generadas in situ.
Variación del ligando para controlar la selectividad de la reacción y la formación del producto.

Principales resultados:

Anulación exitosa por primera vez de alenos cíclicos tensados con paladio.
Síntesis selectiva de dos estructuras isoméricas policíclicas distintas.
Formación de productos heterocíclicos ricos en sp3 con múltiples estereocentros.

Conclusiones:

Este trabajo establece un nuevo método para utilizar alenos cíclicos tensados en síntesis.
La metodología desarrollada permite el ensamblaje rápido de arquitecturas moleculares complejas.
Se alienta a una mayor exploración de los acoplamientos catalizados por metales de transición con allenes cíclicos tensados.

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