- Iridium-Catalyzed Domino Hydroformylation/Hydrogenation of Olefins to Alcohols: Synergy of Two Ligands
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A novel one-pot iridium-catalyzed domino hydroxymethylation of olefins, which relies on using two different ligands at the same time, is reported. DFT computation reveals different activities for the individual hydroformylation and hydrogenation steps in the presence of mono- and bidentate ligands. Whereas bidentate ligands have higher hydrogenation activity, monodentate ligands show higher hydroformylation activity. Accordingly, a catalyst system is introduced that uses dual ligands in the whole domino process. Control experiments show that the overall selectivity is kinetically controlled. Both computation and experiment explain the function of the two optimized ligands during the domino process.
- Beller, Matthias,Huang, Weiheng,Jackstell, Ralf,Jiao, Haijun,Tian, Xinxin
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supporting information
(2022/01/13)
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- Selective Production of Linear Aldehydes and Alcohols from Alkenes using Formic Acid as Syngas Surrogate
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Performing carbonylation without the use of carbon monoxide for high-value-added products is an attractive yet challenging topic in sustainable chemistry. Herein, effective methods for producing linear aldehydes or alcohols selectively with formic acid as both carbon monoxide and hydrogen source have been described. Linear-selective hydroformylation of alkenes proceeds smoothly with up to 88 % yield and >30 regioselectivity in the presence of single Rh catalyst. Strikingly, introducing Ru into the system, the dual Rh/Ru catalysts accomplish efficient and regioselective hydroxymethylation in one pot. The present processes utilizing formic acid as syngas surrogate operate simply under mild condition, which opens a sustainable way for production of linear aldehydes and alcohols without the need for gas cylinders and autoclaves. As formic acid can be readily produced via CO2 hydrogenation, the protocols represent indirect approaches for chemical valorization of CO2.
- Chen, Junjun,Hua, Kaimin,Liu, Xiaofang,Deng, Yuchao,Wei, Baiyin,Wang, Hui,Sun, Yuhan
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p. 9919 - 9924
(2021/05/31)
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- Structure-Based Design of β5c Selective Inhibitors of Human Constitutive Proteasomes
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This work reports the development of highly potent and selective inhibitors of the β5c catalytic activity of human constitutive proteasomes. The work describes the design principles, large hydrophobic P3 residue and small hydrophobic P1 residue, that led to the synthesis of a panel of peptide epoxyketones; their evaluation and the selection of the most promising compounds for further analyses. Structure-activity relationships detail how in a logical order the β1c/i, β2c/i, and β5i activities became resistant to inhibition as compounds were diversified stepwise. The most effective compounds were obtained as a mixture of cis- and trans-biscyclohexyl isomers, and enantioselective synthesis resolved this issue. Studies on yeast proteasome structures complexed with some of the compounds provide a rationale for the potency and specificity. Substitution of the N-terminus in the most potent compound for a more soluble equivalent led to a cell-permeable molecule that selectively and efficiently blocks β5c in cells expressing both constitutive proteasomes and immunoproteasomes.
- Xin, Bo-Tao,De Bruin, Gerjan,Huber, Eva M.,Besse, Andrej,Florea, Bogdan I.,Filippov, Dmitri V.,Van Der Marel, Gijsbert A.,Kisselev, Alexei F.,Van Der Stelt, Mario,Driessen, Christoph,Groll, Michael,Overkleeft, Herman S.
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supporting information
p. 7177 - 7187
(2016/08/24)
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- Ruthenium-catalyzed hydroformylation of alkenes by using carbon dioxide as the carbon monoxide source in the presence of ionic liquids
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The reaction of [BMI·Cl] (BMI=1-butyl-3-methylimidazolium) or [BMMI·Cl] (BMMI=3-butyl-1,2-dimethylimidazolium) with Ru 3(CO)12 generates Ru-hydride-carbonyl-carbene species in situ that are efficient catalysts for a reverse water gas shift/ hydroformylation/hydrogenation cascade reaction. The addition of H 3PO4 increased the catalytic activity of the first step (i.e., the hydrogenation of CO2 to CO). Under the optimized reaction conditions [120°C and 6.0 MPa CO2/H2 (1:1) for 17 h], cyclohexene and 2,2-disubstituted alkenes were easily functionalized to alcohols through sequential hydroformylation/carbonyl reduction.
- Ali, Meher,Gual, Aitor,Ebeling, Guenter,Dupont, Jairton
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p. 2224 - 2228
(2014/08/18)
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- Formic acid: A promising bio-renewable feedstock for fine chemicals
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In light of the growing scarcity of petroleum-based raw materials, carbon dioxide (CO2) is becoming increasing attractive as organic carbon source. In this perspective, formic acid (HCOOH) might be an interesting bio-renewable solution to store, transport, and activate carbon dioxide for the synthesis of value-added chemicals. Herein, HCOOH has been successfully used as C1 building block for the synthesis of a library of alcohols via a catalysed oxo-synthesis, under green experimental conditions. Copyright
- Mura, Manuel G.,Luca, Lidia De,Giacomelli, Giampaolo,Porcheddu, Andrea
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supporting information
p. 3180 - 3186
(2013/01/15)
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- Synthesis and transformation of 5- and 2-methyl-bicyclo[2.2.1]hept-2-enes and 2-methylenebicyclo[2.2.1]heptane with retrospective δ-migration of hydrogen over oxide catalyst
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5- and 2-Methylbicyclo[2.2.1]hept-2-enes and 2-methylenebicyclo[2.2.1] heptane were synthesized by a new procedure, and their transformations in a flow system over stationary layer of aluminosilicate catalyst were studied at various temperatures. At 15-400°C these compounds undergo isomerization which is accompanied by δ-migration of hydrogen. The isomerization mechanism is discussed in terms of formation of classical carbocations, not invoking nonclassical carbenium ion.
- Gasanov
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p. 947 - 951
(2007/10/03)
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- DERMATOLOGICAL COMPOSITIONS AND METHODS
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Disclosed are methods and compositions for regulating the melanin content of mammalian melanocytes; regulating pigmentation in mammalian skin, hair, wool or fur; treating or preventing various skin and proliferative disorders; by administration of various compounds, including alcohols, diols and/or triols and their analogues.
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- Bicyclo[2.2.1]heptane-2-methanol Transformations on oxide catalysts
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Bicyclo[2.2.1]heptane-2-methanol was synthesized by hydrogenation of bicyclo[2.2.1]hept-5-ene-2-methanol in a flow system on fixed-bed oxide catalysts, and its transformations were studied. Dehydration and isomerization of bicycloheptene structure with the double-bond migration were found to be the main transformation routes. Thus, 2-methylenebicyclo[2.2.1]heptane (norcamphene), the product of dehydration, was obtained with 47.2 or 61.0% yield in the presence of γ-Al2O3 or aluminosilicate, respectively. The majority of norcamphene was isomerized to give bi- and monocyclic unsaturated hydrocarbons differing in position of the double bond.
- Gasanov,Alieva,Musaev
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p. 272 - 274
(2007/10/03)
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- Treatment of neurodegenerative diseases
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Disclosed are methods for increasing the differentiation of mammalian neuronal cells for purposes of treating neurodegenerative diseases or nerve damage by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- Treatment of diseases mediated by the nitric oxide/cGMP/protein kinase G pathway
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Disclosed are methods and compositions for stimulating cellular nitric oxide (NO) synthesis, cyclic guanosine monophosphate levels (cGMP), and protein kinase G (PKG) activity for purposes of treating diseases mediated by deficiencies in the NO/cGMP/PKG signal transduction pathway, by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- Synthesis, structure, and transformations of 7-hydroxymethyltetracyclo[6.2.16,9.05,10]dodec-2-ene
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7-Hydroxymethyltetracyclo[6.2.1.16,9.0 5.10]dodec-2-ene was synthesized, and its structure was studied by the molecular mechanics method. The energies of conformers and rotational barriers of the substituent were estimated from the analysis of curves of the dependence of the total steric energy on the C6C7C13O torsion angle. exo-Stereoselectivity of epoxidation of 2-methylenetetracyclo[6.2.1.16,9.05.10]dodecane obtained by three-stage synthesis from the starting alcohol was shown by 1H NMR and quantum-chemical studies by the PM3 method of the potential energy surface by using the reaction of epoxidation of 2-methylenebicyclo[2.2.1]heptane by peroxyformic acid as an example. The difference between the calculated values of activation barriers of the most favorable reaction routes (4.22 kJ/mol) corresponds to an epoxide ratio of 84 : 16 in favor of the exo-isomer and agrees with the experimentally established ratio of the stereoisomers. Analysis of a change in bond and torsion angles during formation of the transition states shows that structural deformations are primarily responsible for stereoselectivity of the process.
- Kas'yan,Okovityi,Seferova
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p. 228 - 233
(2007/10/03)
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- Process for producing an oligomer
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There are disclosed a process for producing an oligomer by oligomerizing a raw material comprising an unsaturated bicyclo heptane derivative and/or an unsaturated bicyclo octane derivative, which comprises the step of restricting the contents of dienes contained in the raw material to at most 1% by weight; and a process wherein the raw material is subjected to solid acid treatment simultaneously with or prior to distillation and then to oligomerization. The above process can efficiently produce the oligomer well suited for use in a traction drive fluid having a low viscosity and exhibiting excellent performance over a wide temperature range.
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- Catalytic procedure for the synthesis of cycloalkanemethanols from cycloalkenes and aqueous methyl formate
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Cycloalkanemethanols are synthesized via hydrocarbonylation (hydroformylation) of the corresponding cycloalkenes in the presence of aqueous methyl formate. Methyl formate is the source of carbon monoxide and hydrogen is generated by the water gas shift reaction. The selectivity is affected by the concomitant hydrogenation process.
- Jenner
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p. 505 - 508
(2007/10/02)
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- Metal Ion Photoinitiated Addition of Acetonitrile and Methanol to Olefins
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Irradiation of norbornene and silver or thallium trifluoromethanesulfonate in acetonitrile solutions results in the efficient formation of exo-2-(cyanomethyl)bicycloheptane.Investigation of the scope of this reaction established that (a) copper(I or II) salts are not effective, (b) propionitrile and methanol give analogous norbornene-solvent adducts, and (c) acetonitrile addition is observed for several cyclic and acyclic olefins.Investigation of the mechanism of solvent addition indicates that the reaction is initiated by photoinduced electron transfer to silver(I) from coordinated norbornene.Reaction of the resulting norbonene cation radical with acetonitrile yields norbornyl cation and cyanomethyl radical.Free-radical chain addition of the cyanomethyl radical to norbornene then leads to product formation.In ethereal solvents, metal ion catalyzed photodimerization of norbornene has previously been reported for copper(I) salts.This reaction can also be effected by copper(II) and silver(I) salts, but not by Tl(I) salts.
- Bruno, Joseph W.,Marks, Tobin J.,Lewis, Frederick D.
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p. 5580 - 5585
(2007/10/02)
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