Oxo-Tethered Ruthenium(II) Complex as a Bifunctional Catalyst for Asymmetric Transfer Hydrogenation and H2 Hydrogenation

Oxo-Tethered Ruthenium(II) Complex as a Bifunctional Catalyst for Asymmetric Transfer Hydrogenation and H2 Hydrogenation:

Journal of the American Chemical Society

DOI: 10.1021/ja207283t

Tuning of the Electronic Properties of a Cyclopentadienylruthenium Catalyst to Match Racemization of Electron-Rich and Electron-Deficient Alcohols

Tuning of the Electronic Properties of a Cyclopentadienylruthenium Catalyst to Match Racemization of Electron-Rich and Electron-Deficient Alcohols:

Abstract

The synthesis of a new series of cyclopentadienylruthenium catalysts with varying electronic properties and their application in racemization of secondary alcohols are described. These racemizations involve two key steps: 1) β-hydride elimination (dehydrogenation) and 2) re-addition of the hydride to the intermediate ketone. The results obtained confirm our previous theory that the electronic properties of the substrate determine which of these two steps is rate determining. For an electron-deficient alcohol the rate-determining step is the β-hydride elimination (dehydrogenation), whereas for an electron-rich alcohol the re-addition of the hydride becomes the rate-determining step. By matching the electronic properties of the catalyst with the electronic properties of the alcohol, we have now shown that a dramatic increase in racemization rate can be obtained. For example, electron-deficient alcohol 15 racemized 30 times faster with electron-deficient catalyst 6 than with the unmodified standard catalyst 4. The application of these protocols will extend the scope of cyclopentadienylruthenium catalysts in racemization and dynamic kinetic resolution.

Finely tuned: Progress has been made in the development of racemization catalysts for secondary alcohols. By tuning the catalyst to match the electronic properties of the substrate, highly efficient racemization protocols for alcohols with varying electronic properties were achieved (see scheme).

Synthesis and characterization of diiron dithiolate complexes containing a quinoxaline bridge

Synthesis and characterization of diiron dithiolate complexes containing a quinoxaline bridge:

Dalton Trans., 2011, Advance Article DOI: 10.1039/C1DT10953G

Fenfen Xu, Shaowu Du, Yuping Liu, Jacqueline Hassan, Jie Zhang, Alan M. Bond
A new 2Fe2S complex [Fe₂{([small mu ]-CH₂S)₂R}(CO)₆] (1) (R = quinoxaline) has been synthesized. The protonation and redox properties of 1 and its dppm-substituted derivatives 2-4 are also studied.

Design and Synthesis of a Novel Triptycene-Based Ligand for Modeling Carboxylate-Bridged Diiron Enzyme Active Sites

Design and Synthesis of a Novel Triptycene-Based Ligand for Modeling Carboxylate-Bridged Diiron Enzyme Active Sites:

Organic Letters

DOI: 10.1021/ol201882v

A Highly Active Catalyst for the Hydrogenation of Amides to Alcohols and Amines

A Highly Active Catalyst for the Hydrogenation of Amides to Alcohols and Amines:

Amide-zing: The reaction between 2 equivalents of Ph₂P(CH₂)₂NH₂ and cis-[Ru(CH₃CN)₂(η³-C₃H₅)(cod)]BF₄ (cod=1,5-cyclooctadiene) forms a highly active catalyst precursor for the selective hydrogenation of amides. The reaction proceeds with excellent atom economy, yield, and turnover numbers (TONs) under moderate reaction conditions. The technology offers a greener, practical approach to the use of metal hydride reagents commonly employed in both academia and industry.

Transformation of Carbon Dioxide with Homogeneous Transition-Metal Catalysts: A Molecular Solution to a Global Challenge?

Transformation of Carbon Dioxide with Homogeneous Transition-Metal Catalysts: A Molecular Solution to a Global Challenge?:

Abstract

A plethora of methods have been developed over the years so that carbon dioxide can be used as a reactant in organic synthesis. Given the abundance of this compound, its utilization in synthetic chemistry, particularly on an industrial scale, is still at a rather low level. In the last 35 years, considerable research has been performed to find catalytic routes to transform CO₂ into carboxylic acids, esters, lactones, and polymers in an economic way. This Review presents an overview of the available homogeneous catalytic routes that use carbon dioxide as a C₁ carbon source for the synthesis of industrial products as well as fine chemicals.

Renewable carbon resources, such as carbon dioxide, are of enormous interest as an entry into industrially relevant chemicals, such as formic or salicylic acids, urea, and (poly)carbonates. This Review highlights the use of CO₂ as a C₁ feedstock as well as its transformation with homogeneous molecular transition-metal catalysts.

Geometric and Electronic Structures of Peroxomanganese(III) Complexes Supported by Pentadentate Amino-Pyridine and -Imidazole Ligands

Geometric and Electronic Structures of Peroxomanganese(III) Complexes Supported by Pentadentate Amino-Pyridine and -Imidazole Ligands:

Inorganic Chemistry

DOI: 10.1021/ic201168j

Multiple Structures and Dynamics of [CpRu(CO)2]2 and [CpFe(CO)2]2 in Solution Revealed with Two-Dimensional Infrared Spectroscopy

Multiple Structures and Dynamics of [CpRu(CO)2]2 and [CpFe(CO)2]2 in Solution Revealed with Two-Dimensional Infrared Spectroscopy:

Inorganic Chemistry

DOI: 10.1021/ic200466b

Activation of CO2 by a Heterobimetallic Zr/Co Complex

Activation of CO2 by a Heterobimetallic Zr/Co Complex:

Journal of the American Chemical Society

DOI: 10.1021/ja2071847

Water Oxidation by a Mononuclear Ruthenium Catalyst: Characterization of the Intermediates

Water Oxidation by a Mononuclear Ruthenium Catalyst: Characterization of the Intermediates:

Journal of the American Chemical Society

DOI: 10.1021/ja203249e

A Highly Active Catalyst for the Hydrogenation of Amides to Alcohols and Amines

A Highly Active Catalyst for the Hydrogenation of Amides to Alcohols and Amines:

Amide-zing: The reaction between 2 equivalents of Ph₂P(CH₂)₂NH₂ and cis-[Ru(CH₃CN)₂(η³-C₃H₅)(cod)]BF₄ (cod=1,5-cyclooctadiene) forms a highly active catalyst precursor for the selective hydrogenation of amides. The reaction proceeds with excellent atom economy, yield, and turnover numbers (TONs) under moderate reaction conditions. The technology offers a greener, practical approach to the use of metal hydride reagents commonly employed in both academia and industry.

Synthesis and Property of Diruthenium Complexes Containing Bridging Cyclic Diene Ligands and the Reaction of Diruthenium Tetrahydrido Complex with Benzene Forming a μ-η2:η2-Cyclohexadiene Complex via Partial Hydrogenation on a Ru2 Center

Synthesis and Property of Diruthenium Complexes Containing Bridging Cyclic Diene Ligands and the Reaction of Diruthenium Tetrahydrido Complex with Benzene Forming a μ-η2:η2-Cyclohexadiene Complex via Partial Hydrogenation on a Ru2 Center:

Organometallics

DOI: 10.1021/om200728e

Immobilization, Trapping, and Anion Exchange of Perrhenate Ion Using Copper-Based Tripodal Complexes

Immobilization, Trapping, and Anion Exchange of Perrhenate Ion Using Copper-Based Tripodal Complexes:

Inorganic Chemistry

DOI: 10.1021/ic201172r

Copper-Catalyzed Trifluoromethylation of Unactivated Olefins

Copper-Catalyzed Trifluoromethylation of Unactivated Olefins:

Activating the inactive: A copper-catalyzed allylic trifluoromethylation of unactivated terminal olefins proceeds under mild conditions to produce linear allylic trifluoromethylated products with high E/Z selectivity (see scheme). The reaction can be applied to a range of substrates bearing numerous functional groups. Furthermore, the reaction is scalable and amenable to a benchtop setup.

Would Chris's complexes or even Cu(TPA) do this reaction better?

Iridium Diamine Catalyst for the Asymmetric Transfer Hydrogenation of Ketones

Iridium Diamine Catalyst for the Asymmetric Transfer Hydrogenation of Ketones:

A simple and very efficient chiral aqua iridium(III) diamine complex leads to excellent enantioselectivities in the asymmetric transfer hydrogenation of various α-cyano and α-nitro ketones. The catalyst provides the ortho-substituted aromatic alcohols with high ee values. The diamine ligands can be used directly as chiral ligands; conversion to the corresponding sulfamide is not necessary.

How do the get the N,N'-dimethylDPEN?

Synthetic and Structural Characterization of Linear and Macrocyclic Ni/Fe/E (E = S, Se) Cluster Complexes

Synthetic and Structural Characterization of Linear and Macrocyclic Ni/Fe/E (E = S, Se) Cluster Complexes:

Organometallics

DOI: 10.1021/om2004767

Active-Site Models for the Nickel–Iron Hydrogenases: Effects of Ligands on Reactivity and Catalytic Properties

Active-Site Models for the Nickel–Iron Hydrogenases: Effects of Ligands on Reactivity and Catalytic Properties:

Inorganic Chemistry

DOI: 10.1021/ic2012759

Recent developments of molybdenum and tungsten sulfides as hydrogen evolution catalysts

Recent developments of molybdenum and tungsten sulfides as hydrogen evolution catalysts:

Energy Environ. Sci., 2011, Advance Article
DOI: 10.1039/C1EE01970H, Perspective

Daniel Merki, Xile Hu
This perspective presents the recent developments of molybdenum and tungsten sulfide materials as hydrogen evolution catalysts.
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Hydrogen evolution at polarised liquid/liquid interfaces catalyzed by molybdenum disulfide

Hydrogen evolution at polarised liquid/liquid interfaces catalyzed by molybdenum disulfide:

Energy Environ. Sci., 2011, Advance Article
DOI: 10.1039/C1EE01996A, Paper

Imren Hatay, Pei Yu Ge, Heron Vrubel, Xile Hu, Hubert H. Girault
Molybdenum disulfide (MoS₂) microparticles in an aqueous acidic solution are shown to be an effective catalyst for hydrogen evolution by electron donor decamethylferrocene (DMFc) at the water/1,2-dichloroethane interface.
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The Complete Characterization of a Reduced Biomimetic [2 Fe-2 S] Cluster

The Complete Characterization of a Reduced Biomimetic [2 Fe-2 S] Cluster:

Cores and effect: A biomimetic [2 Fe-2 S] cluster is characterized crystallographically in both the [Fe^IIIFe^III] and the mixed-valent [Fe^IIIFe^II] forms—the [2 Fe-2 S] cores show only minor geometric differences. The reduced form has an S=1/2 ground state and the unpaired electron is partially delocalized over the cluster core. The experimental effective coupling constant predicts the position of the intervalence charge transfer band in the IR regime.

Separating Electrophilicity and Lewis Acidity: The Synthesis, Characterization, and Electrochemistry of the Electron Deficient Tris(aryl)boranes B(C6F5)3–n(C6Cl5)n (n = 1–3)

Separating Electrophilicity and Lewis Acidity: The Synthesis, Characterization, and Electrochemistry of the Electron Deficient Tris(aryl)boranes B(C6F5)3–n(C6Cl5)n (n = 1–3):

Journal of the American Chemical Society ASAP

DOI: 10.1021/ja205037t

Stereomutation in Trigonal-Bipyramidal Systems: A Unified Picture

Stereomutation in Trigonal-Bipyramidal Systems: A Unified Picture:

Same difference: Berry pseutorotation (BPR) and Ugi turnstile rotation, which are generally treated as two distinctly different mechanisms for rearrangement of trigonal-bipyramidal structures, have been shown to be equivalent. Alternative mechanisms consist of sequences of pseudorotations proceeding in a single step.

Direct electrochemistry of an [FeFe]-hydrogenase on a TiO2 Electrode

Direct electrochemistry of an [FeFe]-hydrogenase on a TiO2 Electrode:

Chem. Commun., 2011, Advance Article
DOI: 10.1039/C1CC14535E, Communication

Simone Morra, Francesca Valetti, Sheila J. Sadeghi, Paul W. King, Toby Meyer, Gianfranco Gilardi
Immobilization of the recombinant [FeFe]-hydrogenase was achieved for the first time on anatase TiO₂ catalyzing hydrogen production with a 70% efficiency.

Dynamic Multicomponent Hemiaminal Assembly

Dynamic Multicomponent Hemiaminal Assembly:

Eur J Chem

A simple approach to generating in situ metal-templated tris-(2-picolyl)amine-like multicomponent assemblies with potential applications in molecular recognition and sensing is reported. The assembly is based on the reversible covalent association between di-(2-picolyl)amine and aldehydes. Zinc ion is best for inducing assembly among the metal salts investigated, whereas 2-picolinaldehyde is the best among the heterocyclic aldehydes studied. Although an equilibrium constant of 6.6×10³ M⁻¹ was measured for the assembly formed by 2-picolinaldehdye, di-(2-picolyl)amine, and zinc triflate, the equilibrium constants for other systems are in the 10² M⁻¹ range. X-ray structural analysis revealed that zinc adopts trigonal-bipyramidal geometry within the assembled ligand. The diversity and equilibrium of the assemblies are readily altered by simply changing concentrations, varying components, or adding counteranions.

Change the diversity! A simple metal-mediated multicomponent assembly based on reversible covalent bond formation is described (see scheme). The diversity of the system can be easily varied with the potential for dynamic combinatorial library creation and subsequent molecular recognition.

Variable coordination of amine functionalised N-heterocyclic carbene ligands to Ru, Rh and Ir: C-H and N-H activation and catalytic transfer hydrogenation

Variable coordination of amine functionalised N-heterocyclic carbene ligands to Ru, Rh and Ir: C-H and N-H activation and catalytic transfer hydrogenation:

Dalton Trans., 2011, Advance Article DOI: 10.1039/C1DT10753D, Paper

Warren B. Cross, Christopher G. Daly, Youcef Boutadla, Kuldip Singh
Reactions of amine functionalised imidazolium salts with half-sandwich Ru(II), Rh(III) and Ir(III) halides are reported, including the first primary amine- or amido-NHC complexes of Rh and Ir.

The recipe for TH (transfer hydrogenation). M-H and N-H together. Usually N-H is NH2 tethered to PR3 or NTs.

Targeted and multifunctional arene ruthenium chemotherapeutics

Targeted and multifunctional arene ruthenium chemotherapeutics:

Dalton Trans., 2011, Advance Article
DOI: 10.1039/C1DT11007A, Perspective

Gregory S. Smith, Bruno Therrien
This perspective review presents an overview of ruthenium complexes with biologically active molecules that produce bioorganometallic molecules of chemotherapeutic significance.

I (TR) dont think that the medical apps are very realistic (otherwise pharma would be more deeply into this area), but the chemistry is fascinating. This is the group that popularized [(C6Me6)Ru(H2O)3]++.

New possible mode of ligand-metal cooperation in PC(sp3)P pincer complexes

New possible mode of ligand-metal cooperation in PC(sp3)P pincer complexes:

Dalton Trans., 2011, 40,8760-8763
DOI: 10.1039/C1DT10167F, Communication

Sanaa Musa, Ronit Romm, Clarite Azerraf, Sebastian Kozuch, Dmitri Gelman
Ligand-metal cooperation in iridium and platinum complexes bearing tricyclic dibenzobarrelene-based PC(sp³)P pincer ligands is discussed.

interesting 3-dimensional diphosphine

Iron(0) Promotes Aza Cyclization of an Elusive Ferrocenylketene

Iron(0) Promotes Aza Cyclization of an Elusive Ferrocenylketene:

Organometallics

DOI: 10.1021/om200302z