- Enhanced chemoselective hydrogenation through tuning the interaction between pt nanoparticles and carbon supports: Insights from identical location transmission electron microscopy and x?ray photoelectron spectroscopy
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Ultrasmall-sized platinum nanoparticles (Pt NPs) (~1 nm) supported on carbon nanotubes (CNTs) with nitrogen doping and oxygen functional groups were synthesized and applied in the catalytic hydrogenation of nitroarenes. The advanced identical location transmission electron microscopy (IL-TEM) method was applied to probe the structure evolution of the Pt/CNT catalysts in the reaction. The results indicate that Pt NPs supported on CNTs with a high amount of nitrogen doping (Pt/H-NCNTs) afford 2-fold activity to that of Pt NPs supported on CNTs with oxygen functional groups (Pt/oCNTs) and 4-fold to that of the commercial Pt NPs supported on active carbon (Pt/C) catalyst toward nitrobenzene. The catalytic performance of Pt/H-NCNTs remained constant during four cycles, whereas the activity of the Pt/oCNTs was halved at the second cycle. Compared with Pt/oCNTs, Pt/H-NCNTs exhibited a higher selectivity (>99%) in chemoselective hydrogenation of halonitrobenzenes to haloanilines due to the electron-rich chemical state of Pt NPs. The strong metal?support interaction along with the electron-donor capacity of nitrogen sites on H-NCNTs are capable of stabilizing the Pt NPs and achieving related catalytic recyclability as well as approximately 100% selectivity. The catalyst also delivers exclusively selective hydrogenation toward nitro groups for a wide scope of substituent nitroarenes into their corresponding anilines.
- Shi, Wen,Zhang, Bingsen,Lin, Yangming,Wang, Qi,Zhang, Qiang,Su, Dang Sheng
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- Efficient and highly selective boron-doped carbon materials-catalyzed reduction of nitroarenes
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Exploring the potential catalytic applications of boron-doped carbon materials is a fascinating challenge. Here we describe that boron-doped onion-like carbon and carbon nanotubes as metal-free catalysts exhibit excellent catalytic activity and stability in nitroarene reduction under a stoichiometric amount of reductant.
- Lin, Yangming,Wu, Shuchang,Shi, Wen,Zhang, Bingsen,Wang, Jia,Kim, Yoong Ahm,Endo, Morinobu,Su, Dang Sheng
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p. 13086 - 13089
(2015/08/18)
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- Reductive monoalkylation of nitro aryls in one-pot
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The scope of the serendipitous reductive monoalkylation of ethyl (4-methoxy-3-nitrophenyl) acetate taking place during reduction of the nitro functionality to the corresponding primary amine when treated with hydrogen (1 atm) over Pd/C (10%) in ethanol is investigated. Upon prolonged reaction time the reaction conducted in ethanol and methanol yields significant amount of the corresponding secondary amines, while when performed in n-butanol and i-propanol it only resulted in the formation of a small amount of the corresponding secondary amines. Further development of the reductive monoalkylation reaction provided conditions that facilitate conversion of a range of different nitro aryls in one-pot to the corresponding secondary benzyl amino aryls in mostly good to excellent yields. This is accomplished by using hydrogen (1 atm) over Pd/C (10%) as reducing agent and benzaldehyde as the benzyl source combined with a stepwise reaction sequence. This chemistry was further extended to the formation of substituted benzyl amino aryls. The yields of the latter products varied dramatically depending on the substitution patterns associated with the benzaldehyde. However, by altering the reaction conditions it was possible to improve the yields of the benzylated products.
- Sydnes, Magne O.,Kuse, Masaki,Isobe, Minoru
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p. 6406 - 6414
(2008/09/21)
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- Synthesis of the second generation photoaffinity probes of tautomycin
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Five photoaffinity probes of tautomycin, which possess an aromatic azide with linker attached to the 2-position of tautomycin, were prepared in order to study the binding site of tautomycin with protein phosphatase 1γ. The photoaffinity probes were synthe
- Sydnes, Magne O.,Isobe, Minoru
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p. 2593 - 2603
(2007/10/03)
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- HETEROYCLYLPHENYL-AND HETEROCYCLYLPYRIDYL-SUBSTITUTED AZOLECARBOXAMIDES AS HERBICIDES
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Compounds of Formula (I), and their N-oxides and agriculturally suitable salts, are disclosed which are useful for controlling undesired vegetation : wherein (J) is (J-1), (J-2), (J-3), (J-4), (J-5), (J-6), (J-7), (J-8), or (J-9) ; R5 is a phenyl ring or a 5- or 6-membered heteroaromatic ring which includes at least one heteroatom selected from N, O and S, each ring optionally substituted with one or more substituents selected from R15; or R5 is a 5- or 6-membered partially unsaturated heterocyclic ring which includes at least one heteroatom selected form N, O and S, the ring connected through a nitrogen atom or an sp2 carbon atom to the remainder of Formula (I) and optionally substituted by one or more substituents selected from R16; and R1a, R1b, R2a, R2b, R3, R4, R15, R16, T, U, W, Y and Z are as defined in the disclosure.
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Page/Page column 69
(2010/02/11)
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- AZOLECARBOXAMIDE HERBICIDES
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Compounds of Formula (I), and their N-oxides and agriculturally suitable salts, are disclosed which are useful for controlling undesired vegetation, wherein J is (J-1), (J-2,(J-3), (J-4), (J-5), (J-6), (J-7), (J-8) and R1a, R1b, R1c, R2a, R2b, R3, R4, R05, T, U, W, Y and Z are as defined in the disclosure. Also disclosed are compositions containing the compounds of Formula (I) and a method for controlling undesired vegetation which involves contacting the vegetation or its environment with an effective amount of a compound of Formula (I). Also disclosed are mixtures and compositions comprising a herbicidally effective amount of a compound of Formula (Iz) wherein J, R1a, R1b, R1c, R2a, R2b, R3, R4, R05, T, U, W, Y and Z are as defined in the disclosure; and an effective amount of another herbicide or herbicide safener. Also disclosed is a method for selectively controlling undesired vegetation in a crop that involves contacting the locus of a crop with an effective amount of a compound of Formula (Iz) and a effective amount of a safener.
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