- Selective hydrothermal reductions using geomimicry
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Reduction of carbon-carbon π-bonds has been demonstrated using iron powder as the reductant and simple powdered nickel as the catalyst in water as the solvent at 250 °C and the saturated water vapor pressure, 40 bars. Stereochemical, kinetic and electronic probes of the mechanism suggest reaction via a conventional Horiuti-Polyani process for hydrogenation at the nickel metal surface. Selective reduction of carbon-carbon π-bonds is observed in the presence of other functional groups. The reactions use benign and Earth-abundant reagents that are at low depletion risk and take place in water as the only solvent under conditions that are characteristic of many geochemical processes.
- Bockisch, Christiana,Lorance, Edward D.,Shaver, Garrett,Williams, Lynda B.,Hartnett, Hilairy E.,Shock, Everett L.,Gould, Ian R.
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p. 4159 - 4168
(2019/08/07)
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- Simple and Clean Photoinduced Aromatic Trifluoromethylation Reaction
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We describe a simple, metal-and oxidant-free photochemical strategy for the direct trifluoromethylation of unactivated arenes and heteroarenes under either ultraviolet or visible light irradiation. We demonstrated that photoexcited aliphatic ketones, such as acetone and diacetyl, can be used as promising low-cost radical initiators to generate CF3 radicals from sodium triflinate efficiently. The broad utility of this strategy and its benefit to medicinal chemistry are demonstrated by the direct trifluoromethylation of unprotected bidentate chelating ligand, xanthine alkaloids, nucleosides, and related antiviral drug molecules.
- Li, Lu,Mu, Xiaoyue,Liu, Wenbo,Wang, Yichen,Mi, Zetian,Li, Chao-Jun
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supporting information
p. 5809 - 5812
(2016/06/09)
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- Introducing a new radical trifluoromethylation reagent
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Perfluoro-3-ethyl-2,4-dimethyl-3-pentyl radical (PPFR) is a persistent radical stable at room temperature, but easily decomposes at 90 °C to produce a CF3 radical which is able to react with a variety of aromatic compounds to afford the corresponding trifluoromethyl derivatives, usually as mixtures of regioisomers in good to excellent overall yields.
- Sato, Azusa,Han, Jianlin,Ono, Taizo,Wzorek, Alicja,Ace?a, José Luis,Soloshonok, Vadim A.
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supporting information
p. 5967 - 5970
(2015/03/30)
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- Iron-catalysed, general and operationally simple formal hydrogenation using Fe(OTf)3 and NaBH4
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An operationally simple and environmentally benign formal hydrogenation protocol has been developed using highly abundant iron(iii) salts and an inexpensive, bench stable, stoichiometric reductant, NaBH4, in ethanol, under ambient conditions. This reaction has been applied to the reduction of terminal alkenes (22 examples, up to 95% yield) and nitro-groups (26 examples, up to 95% yield). Deuterium labelling studies indicate that this reaction proceeds via an ionic rather than radical mechanism.
- MacNair, Alistair J.,Tran, Ming-Ming,Nelson, Jennifer E.,Sloan, G. Usherwood,Ironmonger, Alan,Thomas, Stephen P.
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supporting information
p. 5082 - 5088
(2014/07/08)
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- Pd0-mediated rapid coupling of methyl iodide with excess amounts of benzyl- and cinnamylboronic acid esters: Efficient method for incorporation of positron-emitting 11C radionuclide into organic frameworks by coupling between two sp<
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Pd0-mediated rapid cross coupling between sp3- hybridized carbons of CH3I and benzyl- or cinnamylboronic acid esters using [Pd{P(tert-C4H9)3}2]/CsF in DMF/H2O gave the
- Koyama, Hiroko,Zhang, Zhouen,Ijuin, Ryosuke,Siqin,Son, Jeongwan,Hatta, Yuma,Ohta, Masashi,Wakao, Masahiro,Hosoya, Takamitsu,Doi, Hisashi,Suzuki, Masaaki
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p. 9391 - 9401
(2013/07/27)
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- The use of ultrasmall iron(0) nanoparticles as catalysts for the selective hydrogenation of unsaturated C-C bonds
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The performance of well-defined ultrasmall iron(0) nanoparticles (NPs) as catalysts for the selective hydrogenation of unsaturated C-C and CX bonds is reported. Monodisperse iron nanoparticles of about 2 nm size are synthesized by the decomposition of {Fe(N[Si(CH3)3]2) 2}2 under dihydrogen. They are found to be active for the hydrogenation of various alkenes and alkynes under mild conditions and weakly active for CO bond hydrogenation.
- Kelsen, Vinciane,Wendt, Bianca,Werkmeister, Svenja,Junge, Kathrin,Beller, Matthias,Chaudret, Bruno
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p. 3416 - 3418
(2013/05/22)
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- Intermolecular hydroarylation of unactivated olefins catalyzed by homogeneous platinum complexes
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Designing catalysts: The five-coordinate platinum(IV) complex A and the platinum(II) trans complex B act as precatalysts for the hydroarylation of unactivated olefins. The catalytic cycle features an aryl-olefin insertion at PtII and a C-H bond activation of the arene solvent as key steps. The Pt II cis complex C has been observed in hydroarylation reactions of ethylene with benzene.
- Luedtke, Avery T.,Goldberg, Karen I.
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supporting information; experimental part
p. 7694 - 7696
(2009/04/11)
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- Efficient access to 3-alkyl-trifluoromethylbenzenes using Kumada's coupling reaction
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3-Alkyl-trifluoromethylbenzenes are obtained in good yields by Kumada's coupling reaction between methyl or ethyl magnesium halide and 3-bromo-trifluoromethylbenzene derivatives in the presence of Ni-Xantphos catalyst.
- Roques, Nicolas,Saint-Jalmes, Laurent
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p. 3375 - 3378
(2007/10/03)
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- Highly regioselective hydrogenolysis of bis(α-methylbenzyl)amine derivatives affected by the trifluoromethyl substituent on the aromatic ring
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(Matrix presented) The highly regioselective hydrogenolysis of bis(α-methylbenzyl)amine derivatives proceeded with influence not from the electronic effect but from the steric effect of the trifluoromethyl substituent on the aromatic ring to provide a practical asymmetric synthesis of trifluoromethyl-substituted α-phenylethylamines.
- Kanai, Masatomi,Yasumoto, Manabu,Kuriyama, Yokusu,Inomiya, Kenjin,Katsuhara, Yutaka,Higashiyama, Kimio,Ishii, Akihiro
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p. 1007 - 1010
(2007/10/03)
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- Amination of aromatic olefins with anilines: A new domino synthesis of quinolines
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A new catalytic amination of aromatic olefins with anilines is presented. In a domino reaction, substituted quinoline derivatives are obtained in the presence of cationic rhodium complexes, such as [Rh(cod)2]BF4, and PPh3. Ethylbenzene is formed as a by-product in this new oxidative reaction. The first transition metal catalyzed anti-Markovnikov hydroamination of styrene with anilines occurs as a side reaction. Mechanistic investigations strongly support the regioselective oxidative amination of styrene as the key reaction step.
- Beller, Matthias,Thiel, Oliver R.,Trauthwein, Harald,Hartung, Christian G.
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p. 2513 - 2522
(2007/10/03)
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- The first rhodium-catalyzed anti-markovnikov hydroamination: Studies on hydroamination and oxidative amination of aromatic olefins
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The first transition-metal-catalyzed regiospecific anti-Markovnikov hydroamination of aromatic olefins is reported. Styrene and substituted styrenes react with secondary aliphatic amines, especially morpholine and Narylpiperazines, in the presence of cationic rhodium complexes to give 2- aminoethenylbenzene and 2-aminoethylbenzene derivatives. Cationic [Rh(cod)2]+BF4- and various phosphines (l:2-mixture) were employed as in situ catalysts. According to labeling experiments, there is no evidence that the hydroamination is a consecutive hydrogenation of a previously formed enamine. Hydroamination with simple secondary amines, for example piperidine, can also be achieved by the use of a higher olefin concentration and higher reaction temperatures than those given in previously published reaction procedures. Kinetic investigations of the major reaction pathway reveal that the reaction rate of the oxidative amination and the hydroamination is dependent on the styrene and on the catalyst concentration, and independent of the amine concentration. Experiments that employed deuterium-labeled amines (N-D) provided evidence that the mechanism involves an amine- activating pathway. The substituents on the styrene, the phosphine ligand, and the solvent influence the yield of the aminations and the enamine:alkylamine ratio.
- Beller,Trauthwein,Eichberger,Breindl,Herwig,Mueller,Thiel
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p. 1306 - 1319
(2007/10/03)
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