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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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Construcción catalítica asimétrica de centros de carbono estereogénico halogenado por reacción directa de tipo

Feng Zhong¹, Wen-Jun Yue¹, Hai-Jun Zhang¹

¹CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis , Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , China.

Journal of the American Chemical Society

|November 3, 2018

Resumen

Este estudio presenta un nuevo método catalítico para la creación de centros estereogénicos alílicos halogenados. Este enfoque permite la síntesis de productos intermedios clave para productos farmacéuticos quirales, mostrando sus aplicaciones prácticas.

Área de la Ciencia:

Química orgánica
Síntesis asimétrica
Catálisis

Sus antecedentes:

Las reacciones de tipo Vinylogous Mannich son cruciales para la formación de enlaces C-C.
El desarrollo de métodos enantioselectivos para compuestos halogenados sigue siendo un desafío.

Objetivo del estudio:

Para revelar una nueva reacción catalítica asimétrica viníloga de tipo Mannich.
Para sintetizar centros estereogénicos alílicos halogenados con alta selectividad.

Principales métodos:

Se utilizan γ-halo-α, N-acilpirazoles y N-Boc-aldiminas no saturados.
Se empleó un enfoque asimétrico catalítico.
Se han investigado las reacciones subsiguientes de sustitución nucleofílica y alquilación.

Principales resultados:

Se obtienen altos rendimientos de centros estereogénicos alílicos halogenados (F, Cl, Br).
Se ha demostrado que es bueno para elevadas selectividades regionales, diastéricas y enantiológicas.
Demostró la utilidad del producto bromado en las reacciones S_N2' y S_N2.

Conclusiones:

La metodología desarrollada proporciona un acceso eficiente a bloques de construcción quirales valiosos.
Esta reacción es aplicable a la síntesis asimétrica de productos farmacéuticos intermedios, como las piperidinas 2,3-disubstituidas.

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