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Control del oxígeno estereogénico en un ion oxonio helicoidal

Owen Smith¹, Mihai V Popescu^1,2, Madeleine J Hindson¹

¹Chemistry Research Laboratory, University of Oxford, Oxford, UK.

|March 16, 2023

Resumen

Los investigadores desarrollaron un ion triarioxonio quiral estable, superando la reactividad típica de dichos compuestos. Este avance permite que el oxígeno sirva como el único centro estereogénico en una molécula configuradamente estable.

Área de la Ciencia:

Estereoquímica
Química sintética
Química orgánica

Sus antecedentes:

Los estereocentros de carbono tetraédricos son estables y controlables en la síntesis.
Los compuestos de nitrógeno, fósforo y azufre trisubstituidos se someten a una inversión piramidal.
La estereoquímica de los iones de oxonio está poco desarrollada, con aplicaciones sintéticas limitadas.

Objetivo del estudio:

Diseñar, sintetizar y caracterizar los iones de oxonio de configuración estable.
Para superar la baja barrera de inversión y la alta reactividad típicamente asociada con los iones oxonio.
Para establecer los iones oxonio como determinantes de la configuración en la química sintética.

Principales métodos:

Enfoques combinados de cálculo químico sintético y cuántico.
Restricción geométrica para evitar la inversión piramidal del par solitario de oxígeno.
Caracterización de un ion triarioxonio helicoidal y quiral.

Principales resultados:

Diseño y síntesis exitosas de un ion triarioxonio de configuración estable.
Se ha demostrado una alta barrera a la inversión (>110 kJ/mol), lo que permite el aislamiento a temperatura ambiente.
Estableció el átomo de oxígeno como el único centro estereogénico en una molécula quiral no racémica.

Conclusiones:

Los iones de oxonio pueden ser configuradamente estables a través de la restricción geométrica.
Este trabajo presenta el primer ejemplo de una molécula quiral no racémica con un centro de oxígeno estereogénico estable.
El ion triarioxonio desarrollado puede funcionar como determinante de la configuración en la síntesis.

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