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Cambio de 1,2-hidruro enantioselectivo mediado por nitrógeno catalizado por iridio habilitado por interacciones no

Qian-Kun Fan¹, Zi-Qian Bai¹, Gang He^1,2

¹State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.

Journal of the American Chemical Society

|June 3, 2025

Resumen

Se lograron desplazamientos catalizadores enantioselectivos de 1,2-hidruro utilizando una estrategia mediada por nitreno. Este método genera carbocationes y controla la estereoquímica a través de interacciones no covalentes, obteniendo valiosos productos de lactamo.

Área de la Ciencia:

Química orgánica
Catálisis
Estereoquímica

Sus antecedentes:

Los desplazamientos de 1,2-hidruro en los carbocationes suelen ser muy rápidos, lo que dificulta el control enantioselectivo.
Las reacciones convencionales S_N1 y E1 son más lentas que los desplazamientos de 1,2-hidruro.
El desarrollo de métodos catalíticos para los reordenamientos de carbocación enantioselectiva es un obstáculo importante en la síntesis orgánica.

Objetivo del estudio:

Desarrollar un nuevo método catalítico enantioselectivo para los desplazamientos de 1,2-hidruro.
Para generar carbocationes intermedios a través de una vía mediada por nitreno.
Para lograr la síntesis estereocontrolada de moléculas con estereocentros contiguos.

Principales métodos:

Se empleó una estrategia mediada por nitreno que implica la transferencia intramolecular de metal-nitrenoides a los alquenos.
El control de ligandos y las interacciones no covalentes atractivas se utilizaron para facilitar un desplazamiento de 1,2-hidruro controlado estereo.
La metodología se aplicó para sintetizar δ-lactamas con γ,δ-esterocentros.

Principales resultados:

El método desarrollado proporciona δ-lactamas con estereocentros γ,δ contiguos en altos rendimientos.
Se obtuvieron excelentes diastereoselectividades (> 20:1 dr) y enantioselectividades (> 95% ee) para la mayoría de los ejemplos.
El sistema catalítico demostró un amplio alcance de sustrato, alojando varios nucleófilos y moléculas biológicamente relevantes.

Conclusiones:

La estrategia mediada por nitreno permite desplazamientos de 1,2-hidruro altamente enantioselectivos y estereocontrolados.
Las interacciones no covalentes atractivas, en particular las interacciones C-H, son cruciales para dirigir el resultado estereoquímico.
Esta plataforma ofrece un enfoque versátil para sintetizar moléculas quirales complejas en condiciones suaves.

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