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Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
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El punto caliente de antiaromaticidad localizado impulsa las ciclizaciones deshidrogenativas reductoras en bis- y
Zheng Zhou1,2, Dominic T Egger3, Chaowei Hu4
1Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States.
Journal of the American Chemical Society
|June 2, 2022
Resumen
Desarrollamos un nuevo método de ciclización reductora para crear subunidades complejas de grafeno a partir de helicenos. Este cierre de anillo fácil es impulsado por el alivio de la antiaromaticidad, expandiendo las posibilidades sintéticas.
Área de la Ciencia:
- Química orgánica
- Ciencias de los materiales
- Química supramolecular
Sus antecedentes:
- Los helicenos son hidrocarburos aromáticos policíclicos con una estructura helicoidal única.
- Las subunidades de grafeno aniónico son bloques de construcción cruciales para los materiales de carbono avanzados.
- La antiaromaticidad juega un papel importante en la reactividad y estabilidad de los sistemas cíclicos.
Objetivo del estudio:
- Desarrollar un nuevo método de ciclización deshidrogenativa reductora para sintetizar subunidades aniónicas complejas de grafeno.
- Investigar el mecanismo y las fuerzas motrices detrás de estas reacciones de ciclización.
- Explorar la influencia de la antiaromaticidad en la regioselectividad y la eficiencia del proceso.
Principales métodos:
- Ciclización deshidrogenativa reductora de mono- y bis-helicenos con un anillo de cinco miembros incrustado.
- Interrupción de la cascada de reacción con el oxígeno molecular.
- Análisis computacional que incluye análisis de MO, mapas de potenciales electrostáticos moleculares y cálculos NICS ((1.7) ZZ.
Principales resultados:
- Formación de subunidades aniónicas hepta-, nona- y decacíclicas de grafeno.
- Demostración de la doble anulación completa o de las vías de ciclización interrumpida para los bis-helicenos.
- Confirmación de que el alivio de la antiaromaticidad es una fuerza dominante para los cierres de anillos fáciles.
- Identificación del papel de la fracción ciclopentadienilo en la dirección de la carga y la creación de puntos calientes antiaromáticos.
- Validación de la función del alivio de la antiaromaticidad mediante estudios en monohelicenos menos tensos.
Conclusiones:
- La ciclización deshidrogenativa reductora ofrece una ruta versátil para las subunidades aniónicas complejas del grafeno.
- La antiaromaticidad es un factor clave que controla la regioselectividad y la eficiencia de estas reacciones.
- Este método proporciona una alternativa valiosa a las reacciones tradicionales de Scholl para la construcción de sistemas aromáticos policíclicos.
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