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La planaridad no es simple: Reactividad de un arilborano estructuralmente restringido y doblemente reducido hacia los

Christoph D Buch¹, Alexander Virovets¹, Eugenia Peresypkina¹

¹Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt am Main, Germany.

Journal of the American Chemical Society

|May 29, 2025

Resumen

Los 9,10-dihidro-9,10-diboraantracenos (DBA) estructuralmente restringidos activados por dos electrones permiten la activación de moléculas pequeñas de fluorobenzeno. Este estudio revela que los DBA actúan como nucleófilos o agentes reductores, dependiendo del grado de fluoración y contracatión.

Área de la Ciencia:

Química organometálica
Química del grupo principal
Activación de moléculas pequeñas

Sus antecedentes:

Los 9,10-dihidro-9,10-diboraantracenos (DBA) pueden ser activados por inyección de electrones.
Los DBA con limitaciones estructurales ofrecen una mayor estabilidad y una reactividad única.
Los fluorobenzenos son moléculas pequeñas importantes para las transformaciones químicas.

Objetivo del estudio:

Investigar la activación de los fluorobenzenos por un DBA doblemente reducido y estructuralmente restringido.
Elucidar los mecanismos de reacción y los productos de la funcionalización del fluorobenzeno mediada por DBA.
Explorar la influencia del grado de fluoración y la contracatio en la reactividad.

Principales métodos:

Síntesis de sales de dianión de un DBA restringido (M2[1]) y sales radicales (Li[1]).
Reacciones del dianio DBA con varios fluorobenzenos (C6FnH6-n).
Caracterización de productos mediante técnicas experimentales y cálculos químicos cuánticos.

Principales resultados:

El dianio DBA restringido reacciona selectivamente con los fluorobenzenos, formando aductos B ((sp2) / B ((sp3).
Se observaron la monohidrodefluoración y la formación de un adducto de tetrahidrofuran-2-il.
La reactividad varió con el grado de fluoración y la naturaleza del contracatión (Li+, K+).
Se identificaron dos vías de reacción distintas: ataque nucleofílico de tipo S_NAr y transferencia de un solo electrón / abstracción de átomo H.

Conclusiones:

Los DBA doblemente reducidos y restringidos son activadores efectivos de los fluorobenzenos.
El DBA puede actuar como un nucleófilo centrado en B o un agente reductor, dependiendo de las condiciones de reacción.
Este trabajo amplía el alcance de la activación de moléculas pequeñas por compuestos del grupo principal.

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