- Chemoselective and Tandem Reduction of Arenes Using a Metal–Organic Framework-Supported Single-Site Cobalt Catalyst
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The development of heterogeneous, chemoselective, and tandem catalytic systems using abundant metals is vital for the sustainable synthesis of fine and commodity chemicals. We report a robust and recyclable single-site cobalt-hydride catalyst based on a porous aluminum metal–organic framework (DUT-5 MOF) for chemoselective hydrogenation of arenes. The DUT-5 node-supported cobalt(II) hydride (DUT-5-CoH) is a versatile solid catalyst for chemoselective hydrogenation of a range of nonpolar and polar arenes, including heteroarenes such as pyridines, quinolines, isoquinolines, indoles, and furans to afford cycloalkanes and saturated heterocycles in excellent yields. DUT-5-CoH exhibited excellent functional group tolerance and could be reusable at least five times without decreased activity. The same MOF-Co catalyst was also efficient for tandem hydrogenation–hydrodeoxygenation of aryl carbonyl compounds, including biomass-derived platform molecules such as furfural and hydroxymethylfurfural to cycloalkanes. In the case of hydrogenation of cumene, our spectroscopic, kinetic, and density functional theory (DFT) studies suggest the insertion of a trisubstituted alkene intermediate into the Co–H bond occurring in the turnover limiting step. Our work highlights the potential of MOF-supported single-site base–metal catalysts for sustainable and environment-friendly industrial production of chemicals and biofuels.
- Akhtar, Naved,Begum, Wahida,Chauhan, Manav,Manna, Kuntal,Newar, Rajashree,Rawat, Manhar Singh
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supporting information
(2022/01/19)
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- Highly economical and direct amination of sp3carbon using low-cost nickel pincer catalyst
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Developing more efficient routes to achieve C-N bond coupling is of great importance to industries ranging from products in pharmaceuticals and fertilizers to biomedical technologies and next-generation electroactive materials. Over the past decade, improvements in catalyst design have moved synthesis away from expensive metals to newer inexpensive C-N cross-coupling approaches via direct amine alkylation. For the first time, we report the use of an amide-based nickel pincer catalyst (1) for direct alkylation of amines via activation of sp3 C-H bonds. The reaction was accomplished using a 0.2 mol% catalyst and no additional activating agents other than the base. Upon optimization, it was determined that the ideal reaction conditions involved solvent dimethyl sulfoxide at 110 °C for 3 h. The catalyst demonstrated excellent reactivity in the formation of various imines, intramolecularly cyclized amines, and substituted amines with a turnover number (TON) as high as 183. Depending on the base used for the reaction and the starting amines, the catalyst demonstrated high selectivity towards the product formation. The exploration into the mechanism and kinetics of the reaction pathway suggested the C-H activation as the rate-limiting step, with the reaction second-order overall, holding first-order behavior towards the catalyst and toluene substrate.
- Brandt, Andrew,Rangumagar, Ambar B.,Szwedo, Peter,Wayland, Hunter A.,Parnell, Charlette M.,Munshi, Pradip,Ghosh, Anindya
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p. 1862 - 1874
(2021/01/20)
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- A General Catalyst Based on Cobalt Core–Shell Nanoparticles for the Hydrogenation of N-Heteroarenes Including Pyridines
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Herein, we report the synthesis of specific silica-supported Co/Co3O4 core–shell based nanoparticles prepared by template synthesis of cobalt-pyromellitic acid on silica and subsequent pyrolysis. The optimal catalyst material allows for general and selective hydrogenation of pyridines, quinolines, and other heteroarenes including acridine, phenanthroline, naphthyridine, quinoxaline, imidazo[1,2-a]pyridine, and indole under comparably mild reaction conditions. In addition, recycling of these Co nanoparticles and their ability for dehydrogenation catalysis are showcased.
- Beller, Matthias,Chandrashekhar, Vishwas G.,Jagadeesh, Rajenahally V.,Kreyenschulte, Carsten,Murugesan, Kathiravan
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supporting information
p. 17408 - 17412
(2020/08/21)
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- Titanium-Catalyzed Hydroaminoalkylation of Ethylene
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The first examples of titanium-catalyzed hydroaminoalkylation reactions of ethylene with secondary amines are presented. The reactions can be achieved with various titanium catalysts and they do not require the use of high pressure equipment. In addition, the first solid-state structure of a titanapyrrolidine that is formed by insertion of an alkene into the Ti?C bond of a titanaaziridine is reported.
- Rosien, Michael,T?ben, Iris,Schmidtmann, Marc,Beckhaus, Rüdiger,Doye, Sven
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supporting information
p. 2138 - 2142
(2020/02/05)
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- Hydrogenation of Pyridines Using a Nitrogen-Modified Titania-Supported Cobalt Catalyst
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Novel heterogeneous catalysts were prepared by impregnation of titania with a solution of cobalt acetate/melamine and subsequent pyrolysis. The resulting materials show an unusual nitrogen-modified titanium structure through partial implementation of nitrogen into the support. The optimal catalyst displayed good activity and selectivity for challenging pyridine hydrogenation under acid free conditions in water as solvent.
- Chen, Feng,Li, Wu,Sahoo, Basudev,Kreyenschulte, Carsten,Agostini, Giovanni,Lund, Henrik,Junge, Kathrin,Beller, Matthias
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supporting information
p. 14488 - 14492
(2018/10/26)
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- A general and enantiodivergent method for the asymmetric synthesis of piperidine alkaloids: concise synthesis of (R)-pipecoline, (S)-coniine and other 2-alkylpiperidines
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A simple and very efficient protocol for the preparation of highly enantioenriched 2-alkylpiperidines has been set up, which allows the preparation of the final heterocycles with any wanted configuration at the stereogenic center starting from the same starting material. The key step of the synthesis relies on a diastereodivergent aza-Michael reaction protocol using the readily available and cheap reagent (+)-(S,S)-pseudoephedrine as chiral auxiliary.
- Etxebarria, Juan,Vicario, Jose L.,Badía, Dolores,Carrillo, Luisa
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p. 11421 - 11428
(2008/03/13)
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- THERAPEUTIC COMBINATIONS COMPRISING A SELECTIVE ESTROGEN RECEPTOR MODULATOR AND A SELECTIVE ANDROGEN RECEPTOR MODULATOR
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This invention relates to a pharmaceutical combination of a selective estrogen receptor modulator (SERM) and a selective androgen receptor modulator (SARM). Particularly, this invention relates to a pharmaceutical composition comprising cis-6-phenyl-5-(4-(2-pyrrolidin-1-yl-ethoxy)-phenyl)-5,6,7,8-tetrahydronapthalene-2-ol, or a pharmaceutically acceptable salt thereof; and a selective androgen receptor modulator. This invention also relates to methods of treatment using the pharmaceutical composition comprising cis-6-phenyl-5-(4-(2-pyrrolidin-1-yl-ethoxy)-phenyl)-5,6,7,8-tetrahydronapthalene-2-ol, or a pharmaceutically acceptable salt thereof; and a selective androgen receptor modulator. Particularly, this invention is directed to methods to prevent and/or restore age-related decline in muscle mass and strength, treat a wasting disease, treat a condition that prevents with low bone mass, increase muscle mass, increase lean body mass, decrease fat body mass, treat bone fracture and muscle damage and treat female sexual dysfunction in mammals, including humans.
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Page/Page column 19
(2010/10/20)
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- BENZONITRILE DERIVATIVES TO TREAT MUSCULOSKELETAL FRAILTY
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This invention relates to novel amino substituted benzonitrile derivatives and to pharmaceutical compositions containing the novel amino substituted benzonitrile derivatives. This invention also relates to methods of treatment using amino substituted benzonitrile derivatives to prevent and/or restore age-related decline in muscle mass and strength, treat a wasting disease, treat a condition that prevents with low bone mass, increase muscle mass, increase lean body mass, decrease fat body mass, and treat bone fracture and muscle damage in mammals, including humans.
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Page/Page column 14
(2010/02/14)
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- PIPERIDINE-MODIFIED FISCHER-TROPSCH SYNTHESIS
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N-Alkylpiperidines with alkyl fragment length from C1 to C15 were synthesized by the reaction of CO + H2 + piperidine.The molecular mass distribution of the N-alkylpiperidines has two different distribution parameters α.Thus, α = 0.45 +/- 0.03 for C1-C5 alkyl fragments, while α = 0.65 +/- 0.02 for C6-C15.Piperidine was found to act as modifier reagent and chemical trap for the intermediates in the synthesis reaction.
- Kliger, G. A.,Lesik, O. A.,Mikaya, A. I.,Marchevskaya, E. V.,Zaikin, V. G.,et al.
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p. 435 - 438
(2007/10/02)
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- Facile Reduction of Pyridines with Nickel-Aluminum Alloy
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Nickel-aluminum alloy in dilute base can be used to reduce a variety of pyridines, quinolines, and isoquinoline to the corresponding piperidines, 1,2,3,4-tetrahydroquinolines, and 1,2,3,4-tetrahydroisoquinoline in good yield.The reaction is simple to perform, and high temperatures, high pressures, or hydrogen atmospheres are not required.The reaction is accelerated by substituents in the 2-position and by electron-withdrawing groups in the 3- and 4-positions while electron-supplying groups in the 3- and 4-positions retard the reaction.The major product isolated from the reduction of 2-phenylpyridine was 2-cyclohexylpiperidine hydrochloride.With isoniazid (1) and iproniazid (4) the pyridine ring is hydrogenated before the hydrazine is cleaved.
- Lunn, George,Sansone, Eric B.
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p. 513 - 517
(2007/10/02)
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- Alicyclic Nitrosamines and Nitrosamino Acids as Transnitrosating Agents
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Many alicyclic nitrosamines act as nitrosating agents under mild conditions (pH 1-3, in the presence of nucleophilic catalysts such as thiocyanate).All nitrosopiperazines, nitrosomorpholines, and nitrosamino acids tested were found to act as nitrosating agents, and certain nitrosopiperidines also showed this capability.Acyclic nitrosamines are far less reactive than functionally similar cyclic compounds.
- Singer, Sandra S.,Singer, George M.,Cole, Barbara B.
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p. 4931 - 4935
(2007/10/02)
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