Two Copper-Carbenes from One Diazo Compound

Many transition-metal complexes MLn decompose diazo compounds N2-CR1R2 generating metal-carbenes LnM-CR1R2 which transfer the carbene group to other substrates, constituting an important tool in organic synthesis. All previous reports have shown that the CR1R2 fragment at the metal-carbene remains i...

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Detalles Bibliográficos
Autores: Álvarez, María, Besora, María, Molina González, Francisco, Maseras, Feliu, Rodríguez Belderraín, Tomás, Pérez Romero, Pedro José
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universidad de Huelva (UHU)
Repositorio:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Idioma:inglés
OAI Identifier:oai:ariasmontano.uhu.es:10272/19704
Acceso en línea:http://hdl.handle.net/10272/19704
Access Level:acceso abierto
Palabra clave:Metal carbenes
Copper carbenes
Diazo compounds
Carbene decarbolylation
Microkinetic studies
23 Química
Descripción
Sumario:Many transition-metal complexes MLn decompose diazo compounds N2-CR1R2 generating metal-carbenes LnM-CR1R2 which transfer the carbene group to other substrates, constituting an important tool in organic synthesis. All previous reports have shown that the CR1R2 fragment at the metal-carbene remains intact from the parent diazo compound. Herein we report the detection and isolation of a monosubstituted copper carbene where the CR1R2 ligand has undergone a modification from the initial diazo reagent. When TpMsCu(THF) (TpMs = hydrotris(3-mesityl)pyrazolylborate ligand) was reacted with N,N-diethyl diazoacetamide [N2-C(H)(CONEt2)], the stable copper carbene TpMsCu-C(H)(NEt2) was isolated, resulting from a decarbonylation process, with carbon monoxide being trapped as TpMsCu(CO). The simultaneous observation of products derived from the intramolecular carbene insertion reaction into C–H bonds demonstrates that the expected TpMsCu-C(H)(CONEt2) complex is also formed. Experimental data, DFT calculations, and microkinetic models allow us to propose that the latter undergoes CO loss en route to the former.