Ligand Postsynthetic Functionalization with Fluorinated Boranes and Implications in Hydrogenation Catalysis

The incorporation of boron functionalities into transition-metal catalysts has become a promising strategy to improve catalytic performance, although their synthesis typically entails the preparation of sophisticated bifunctional ligands. We report here the facile and direct postsynthetic functional...

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Detalles Bibliográficos
Autores: González Alférez, Macarena, Moreno Díaz, Juan José, Gaona, Miguel A., Maya Díaz, Celia María, Campos, Jesús
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/157966
Acceso en línea:https://hdl.handle.net/11441/157966
https://doi.org/10.1021/acscatal.3c02764
Access Level:acceso abierto
Palabra clave:Hydrogenation
Ligand functionalization
Pendant borane
Rhodium
σ-borane complex
Descripción
Sumario:The incorporation of boron functionalities into transition-metal catalysts has become a promising strategy to improve catalytic performance, although their synthesis typically entails the preparation of sophisticated bifunctional ligands. We report here the facile and direct postsynthetic functionalization of rhodium(I) compound [(η5-C9H7)Rh(PPh3)2] (1) by treatment with perfluorinated boranes. Borane addition to 1 results in an unusual C(sp2)-H hydride migration from the indenyl ligand to the metal with the concomitant formation of a C-B bond. In the case of Piers’ borane [HB(C6F5)2], this is followed by a subsequent hydride migration that leads to an unprecedented 1,2-hydrogen shift reminiscent of Milstein’s cooperative dearomatization pathways. Computational investigations provide a mechanistic picture for the successive hydride-migration steps, which enriches the non-innocent chemistry of widespread indenyl ligands. Moreover, we demonstrate that the addition of Piers’ borane is highly beneficial for catalysis, increasing catalyst efficiency up to 3 orders of magnitude.