title: Cycloaddition Reactions of the Phosphinidene-Bridged Complex [Mo2Cp(μ-κ1:κ1,η5-PC5H4)(CO)2(η6-HMes*)] with Diazoalkanes and Other Heterocumulenes.
abstract: The title phosphinidene complex reacted at room temperature with CS2and SCNPh to give the phosphanyl derivatives [Mo2Cp{μ-κ2P,S:κ1S',η5-P(CS2)C5H4}(CO)2(η6-HMes*)] and [Mo2Cp{μ-κ2P,S:κ1P,η5-P(C(NPh)S)C5H4}(CO)2(η6-HMes*)], respectively (Mes* = 2,4,6-C6H2tBu3), which result from a [2 + 2] cycloaddition of a C═S bond in the organic reagent to the Mo═P bond of the phosphinidene complex, with further insertion of S into the remaining Mo-P bond, in the CS2reaction. The title complex also reacted with diazoalkanes N2CRR' at room temperature to give the corresponding phosphaalkene derivatives [Mo2Cp{μ-η2:κ1P,η5-P(CRR')C5H4}(CO)2(η6-HMes*)] (CRR' = CH2, CPh2, CH(SiMe3)). These products follow from a formal [2 + 1] cycloaddition of the carbene CRR' fragment to the Mo═P bond of the parent compound but were shown to proceed through a [3 + 2] cycloaddition of the diazoalkane molecule, followed by N2elimination. The diazomethane reaction allowed the identification at low temperature of a stabilized form of the intermediate product, the phosphanyl complex [Mo2Cp{μ-κ2P,N:κ1P,η5-P(CHN2H)C5H4}(CO)2(η6-HMes*)], which follows from a reversible 1,3-shift of a methylenic H atom from C to N. It was concluded that all of the above cycloaddition reactions are initiated by heteroatom coordination of the unsaturated organic molecule to the MoCp(CO)2fragment in the parent phosphinidene complex, this triggering the P-C bond formation step which leads to the products eventually isolated. The structures of the new complexes were determined by spectroscopic, diffractometric, and (in some cases) density functional theory methods.
authors.affiliation: Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo , E-33071 Oviedo, Spain.
authors.forename: Isabel G
authors.initials: IG
authors.lastname: Albuerne
authors.affiliation: Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo , E-33071 Oviedo, Spain.
authors.forename: M Angeles
authors.initials: MA
authors.lastname: Alvarez
authors.affiliation: Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo , E-33071 Oviedo, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Amor
authors.affiliation: Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo , E-33071 Oviedo, Spain.
authors.forename: M Esther
authors.initials: ME
authors.lastname: García
authors.affiliation: Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo , E-33071 Oviedo, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: García-Vivó
authors.affiliation: Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo , E-33071 Oviedo, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Ruiz