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Derivados de carborano funcionalizados con boro sin precedentes por activación fácil y selectiva de B-H inducida por
Zhaojin Wang1, Hongde Ye, Yuguang Li
1State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, China.
Journal of the American Chemical Society
|July 10, 2013
Resumen
Este estudio revela nuevos complejos de cobalto de 17 electrones que actúan como intermedios versátiles. Estos complejos permiten la síntesis eficiente de derivados únicos de carborano funcionalizados con boro a través de la activación de B-H mediada por cobalto.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Química del boro y su química.
- Síntesis del carborano.
Sus antecedentes:
- Los complejos de cobalto de 16 electrones sirven como precursores en la síntesis organometálica.
- Los derivados del carborano ofrecen propiedades estructurales y electrónicas únicas.
- El desarrollo de nuevas rutas sintéticas para carboranos funcionalizados está en curso.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos complejos de cobalto de 17 electrones.
- Investigar la reactividad y la utilidad sintética de estos complejos paramagnéticos.
- Desarrollar rutas eficientes mediadas por cobalto para los derivados de carborano funcionalizados con boro.
Principales métodos:
- Reacción de CpCoS2C2B10H10 con varias alquinas.
- Caracterización de complejos de cobalto de 17 electrones y sus derivados.
- Cálculos de la Teoría Funcional de Densidad (DFT) para elucidar los mecanismos de reacción.
- Exploración de la reactividad bajo diferentes condiciones (aire, humedad, sílice, AlCl3, calentamiento).
Principales resultados:
- Formación de dos tipos de complejos de cobalto de 17 electrones (2a-d y 3a-d) con porciones de norbornil carborano.
- Demostración de la escisión del enlace C-S que conduce a derivados de carborano libres de cobalto (4a-d, 5a-d).
- La inserción de alquina en los enlaces Co-S da como resultado carboranos de sulfuro de vinilo (7a-d, 8a-d).
- Productos Retro-Diels-Alder (9a-d) y productos desplazados [1,2]-H (10b,c) observados bajo condiciones específicas.
Conclusiones:
- Los complejos de cobalto de 17 electrones son valiosos intermediarios sintéticos.
- La activación de B-H mediada por cobalto proporciona un acceso eficiente a diversos carboranos funcionalizados con boro.
- Se han establecido nuevas vías sintéticas para los derivados del carborano que no son accesibles por métodos convencionales.
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