σ-Silane Platinum(II) Complexes as Intermediates in C−Si Bond-Coupling Processes
Platinum complexes [Pt(NHC’)(NHC)][BArF] (NHC’ denotes the cyclometallated N-heterocyclic carbene ligand, NHC) react with primary silanes RSiH3 leading to the cyclometallated platinum(II) silyl complexes [Pt(NHC-SiHR’)(NHC)][BArF] through a process that involves the formation of C−Si and Pt−Si bonds...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad de Sevilla (US) |
| Repositorio: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:idus.us.es:11441/137639 |
| Acceso en línea: | https://hdl.handle.net/11441/137639 https://doi.org/10.1002/chem.201902226 |
| Access Level: | acceso abierto |
| Sumario: | Platinum complexes [Pt(NHC’)(NHC)][BArF] (NHC’ denotes the cyclometallated N-heterocyclic carbene ligand, NHC) react with primary silanes RSiH3 leading to the cyclometallated platinum(II) silyl complexes [Pt(NHC-SiHR’)(NHC)][BArF] through a process that involves the formation of C−Si and Pt−Si bonds with concomitant extrusion of H2. Low temperature NMR studies indicate that the process proceeds with the initial formation of the σ-SiH complexes [Pt(NHC’)(NHC)(HSiH2R][BArF] which are stable at temperatures below 0 °C. At higher temperatures activation of one Si−H bond followed by a C−Si coupling reaction generates an agostic SiH platinum hydride derivative [Pt(H)(NHC’- SiH2R)(NHC)][BArF] that undergoes a second SiH bond activation producing the final products. Computational modelling of the reaction mechanism indicate that the stereochemistry of the silyl/hydride ligands after the first Si−H bond cleavage dictates the nature of the products, favoring the formation of a C−Si bond over C−H, in contrast to previous results observed with tertiary silanes. Furthermore, the process involves a trans to cis isomerization of the NHC ligands before the second Si−H bond cleavage |
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