Carbonyl Clusters as Homogeneous Catalysts. Kinetic and Molecular Aspects of the Hydrogenation of Diphenylacetylene Promoted by an Alkenyl-Bridged Triruthenium Cluster Complex

Cabeza, Javier A.; Fernández‐Colinas, José M.; Llamazares, Angela; Riera, Vı́ctor; Garcı́a-Granda, Santiago; Maelen, Juan F. Van der

doi:10.1021/om00023a043

Cited by 44 publications

(27 citation statements)

References 3 publications

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“…Cabeza provided an example of a well-defined triruthenium cluster active in catalysis, where the preformed complex 10 catalyzes the hydrogenation of tolan (11a) to stilbene (12a), as shown in Scheme 5 [72,73]. The authors emphasize that the ampy-NH moiety affords a substrate coordination-wise regioselectivity towards the cis position to the NH coordinated ruthenium center, as CO substitution was consistently observed at this site.…”

Section: Homonuclear Clusters In Catalysis Hydrogenationmentioning

confidence: 99%

Homogeneous Catalysis by Organometallic Polynuclear Clusters

2019

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Homogeneous polynuclear metal clusters constitute a broad class of coordination compounds with important applications in catalysis. The current interest of synthetic chemistry in this field demands the exploration of new strategies to develop catalytic methods that work under mild conditions and maximize atom utilization. This review covers the application of polynuclear clusters of nuclearity ≥3 in homogeneous catalytic processes, with focus on providing an array of examples of various reaction types within cluster catalysis.

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Section: Homonuclear Clusters In Catalysis Hydrogenationmentioning

confidence: 99%

Homogeneous Catalysis by Organometallic Polynuclear Clusters

2019

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“…[5,37] The semi-hydrogenation of diphenylacetylene (DPA) is a conventional model reaction used to evaluate the behavior, mechanisms, and kinetics of the catalytic hydrogenation of internal alkynes. [38][39][40] Herein, we investigated how non-conventional preparation methods (US and MW) of lead-free Pd catalysts may affect the kinetics of DPA semi-hydrogenation.…”

Section: Introductionmentioning

confidence: 99%

Ultrasound‐ and Microwave‐Assisted Preparation of Lead‐Free Palladium Catalysts: Effects on the Kinetics of Diphenylacetylene Semi‐Hydrogenation

Cherkasov

Cravotto

et al. 2015

ChemCatChem

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The effect of environmentally benign enabling technologies such as ultrasound and microwaves on the preparation of the lead‐free Pd catalyst has been studied. A one‐pot method of the catalyst preparation using ultrasound‐assisted dispersion of palladium acetate in the presence of the surfactant/capping agent and boehmite support produced the catalyst containing Pd nanoparticles and reduced the number of pores larger than 4 nm in the boehmite support. This catalyst demonstrated higher activity and selectivity. The comparison of kinetic parameters for diphenylacetylene hydrogenation showed that the catalyst obtained by using the one‐pot method was seven times as active as a commercial Lindlar catalyst and selectivity towards Z‐stilbene was high. Our work also illustrated that highly selective Pd/boehmite catalysts can be prepared through ultrasound‐assisted dispersion and microwave‐assisted reduction in water under hydrogen pressure without any surfactant.

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“…Generally, these reactions are regioselective and only one of the possible alkenyl derivatives is formed, but the factors that govern this regioselectivity have not been studied. In this context, while studying the reactivity of diphenylacetylene with hydrido triruthenium clusters that contain face‐capping 2‐aminopyridine‐derived ligands, namely, [Ru 3 (μ‐H)(μ 3 ‐η 2 ‐RNpy)(CO) 9 ] (where HRNpy represents a 2‐aminopyridine with R on the amino N atom),1f, 2 we observed that only derivatives with edge‐bridging alkenyl ligands have been reported and that the nature of the R group of the ancillary ligand directs the coordination of the alkenyl ligand to the Ru atoms of a particular edge of the metal triangle. Thus, for R=H, both the alkenyl and the amido groups span the same RuRu edge,1f whereas for R≠H, these groups span different RuRu edges2 (e.g., the reactions shown in Scheme ).…”

Section: Introductionmentioning

confidence: 99%

Edge‐Bridging and Face‐Capping Coordination of Alkenyl Ligands in Triruthenium Carbonyl Cluster Complexes Derived from Hydrazines: Synthetic, Structural, Theoretical, and Kinetic Studies

Cabeza¹,

Rı́o²,

Fernández‐Colinas³

et al. 2004

Chemistry A European J

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The reactions of the triruthenium cluster complex [Ru3(mu-H)(mu3-eta2-HNNMe2)(CO)9] (1; H2NNMe2=1,1-dimethylhydrazine) with alkynes (PhC triple bond CPh, HC triple bond CH, MeO2CC triple bond CCO2Me, PhC triple bond CH, MeO2CC triple bond CH, HOMe2CC triple bond CH, 2-pyC triple bond CH) give trinuclear complexes containing edge-bridging and/or face-capping alkenyl ligands. Whereas the edge-bridged products are closed triangular species (three Ru-Ru bonds), the face-capped products are open derivatives (two Ru-Ru bonds). For terminal alkynes, products containing gem (RCCH2) and/or trans (RHCCH) alkenyl ligands have been identified in both edge-bridging and face-capping positions, except for the complex [Ru3(mu3-eta2-HNNMe2)(mu3-eta3-HCCH-2-py)(mu-CO)(CO)7], which has the two alkenyl H atoms in a cis arrangement. Under comparable reaction conditions (1:1 molar ratio, THF at reflux, time required for the consumption of complex 1), some reactions give a single product, but most give mixtures of isomers (not all the possible ones), which were separated. To determine the effect of the hydrazido ligand, the reactions of [Ru3(mu-H)(mu3-eta2-MeNNHMe)(CO)9] (2; HMeNNHMe=1,2-dimethylhydrazine) with PhC triple bond CPh, PhC triple bond CH, and HC triple bond CH were also studied. For edge-bridged alkenyl complexes, the Ru--Ru edge that is spanned by the alkenyl ligand depends on the position of the methyl groups on the hydrazido ligand. For face-capped alkenyl complexes, the relative orientation of the hydrazido and alkenyl ligands also depends on the position of the methyl groups on the hydrazido ligand. A kinetic analysis of the reaction of 1 with PhC[triple chemical bond]CPh revealed that the reaction follows an associative mechanism, which implies that incorporation of the alkyne in the cluster is rate-limiting and precedes the release of a CO ligand. X-ray diffraction, IR and NMR spectroscopy, and calculations of minimum-energy structures by DFT methods were used to characterize the products. A comparison of the absolute energies of isomeric compounds (obtained by DFT calculations) helped rationalize the experimental results.

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Carbonyl Clusters as Homogeneous Catalysts. Kinetic and Molecular Aspects of the Hydrogenation of Diphenylacetylene Promoted by an Alkenyl-Bridged Triruthenium Cluster Complex

Cited by 44 publications

References 3 publications

Homogeneous Catalysis by Organometallic Polynuclear Clusters

Homogeneous Catalysis by Organometallic Polynuclear Clusters

Ultrasound‐ and Microwave‐Assisted Preparation of Lead‐Free Palladium Catalysts: Effects on the Kinetics of Diphenylacetylene Semi‐Hydrogenation

Edge‐Bridging and Face‐Capping Coordination of Alkenyl Ligands in Triruthenium Carbonyl Cluster Complexes Derived from Hydrazines: Synthetic, Structural, Theoretical, and Kinetic Studies

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