C-NH2 bond formation mediated by iridium complexes

In the presence of phosphanes (PR3), the amido-bridged trinuclear complex [{Ir(μ-NH2)(tfbb)}3] (tfbb=tetrafluorobenzobarrelene) transforms into mononuclear discrete compounds [Ir(1,2-η2-4-κ-C12H8F 4N)(PR3)3], which are the products of the C-N coupling between the amido moiety and a vinylic carbon of...

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Detalles Bibliográficos
Autores: Mena, Inmaculada, Casado, Miguel A., Polo, Víctor, García-Orduña, Pilar, Lahoz, Fernando J., Oro, Luis A.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2014
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/111842
Acceso en línea:http://hdl.handle.net/10261/111842
Access Level:acceso abierto
Palabra clave:C-N formation
Amido transfer
N-H activation
Iridium
Ammonia
Descripción
Sumario:In the presence of phosphanes (PR3), the amido-bridged trinuclear complex [{Ir(μ-NH2)(tfbb)}3] (tfbb=tetrafluorobenzobarrelene) transforms into mononuclear discrete compounds [Ir(1,2-η2-4-κ-C12H8F 4N)(PR3)3], which are the products of the C-N coupling between the amido moiety and a vinylic carbon of the diolefin. An alternative synthetic approach to these species involves the reaction of the 18-e- complex [Ir(Cl)(tfbb)(PMePh2)2] with gaseous ammonia and additional phosphane. DFT studies show that both transformations occur through nucleophilic attack. In the first case the amido moiety attacks a diolefin coordinated to a neighboring molecule following a bimolecular mechanism induced by the highly basic NH2 moiety; the second pathway involves a direct nucleophilic attack of ammonia to a coordinated tfbb molecule.