title: Water-Promoted Generation of a Diazairida Homobarrelene by C-C Coupling Between an Iridacyclic Alkylidene and Acetonitrile.
abstract: The stable cationic iridacyclopentenylidene [Tp(Me2)Ir(=CHC(Me)=C(Me)CH2(NCMe)]PF6 (A; Tp(Me2)=hydrotris(3,5-dimethylpyrazolyl)borate) has been obtained by α-hydride abstraction from the iridacyclopent-2-ene [Tp(Me2)Ir(CH2C(Me)=C(Me)CH2)(NCMe)]. Complex A exhibits Brønsted-Lowry acidity at the Ir-CH2 and proximal (relative to Ir-CH2 ) methyl sites. The coordination of an extra molecule of acetonitrile to the iridium center initiates the reversible isomerization of the chelating carbon chain of A to the monodentate butadienyl ligand of complex [Tp(Me2)Ir(CH=C(Me)C(Me)=CH2)(NCMe)2]PF6, which is capable to engage in a water-promoted C-C coupling with the MeCN co-ligands. The product is an aesthetically appealing bicyclic structure that resembles the hydrocarbon barrelene.
authors.affiliation: Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Sevilla, Avda. Américo Vespucio, 49, 41092 Sevilla (Spain).
authors.forename: María F
authors.initials: MF
authors.lastname: Espada
authors.affiliation: Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Sevilla, Avda. Américo Vespucio, 49, 41092 Sevilla (Spain).
authors.forename: Joaquín
authors.initials: J
authors.lastname: López-Serrano
authors.affiliation: Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Sevilla, Avda. Américo Vespucio, 49, 41092 Sevilla (Spain). mpoveda@iiq.csic.es.
authors.forename: Manuel L
authors.initials: ML
authors.lastname: Poveda
authors.affiliation: Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Sevilla, Avda. Américo Vespucio, 49, 41092 Sevilla (Spain). guzman@us.es.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Carmona
keywords: CC coupling; alkylidenes; iridium; water catalysis