F+,
Xi
F+:Highly flammable;Relevant articles and documents
All total 102 Articles be found
All total 102 Articles be foundFalle,Sargent
, p. 3401,3407 (1974)
Development and Application of Efficient Ag-based Hydrogenation Catalysts Prepared from Rice Husk Waste
Unglaube, Felix,Kreyenschulte, Carsten Robert,Mejía, Esteban
, p. 2583 - 2591 (2021/04/09)
The development of strategies for the sustainable management and valorization of agricultural waste is of outmost importance. With this in mind, we report the use of rice husk (RH) as feedstock for the preparation of heterogeneous catalysts for hydrogenation reactions. The catalysts were prepared by impregnating the milled RH with a silver nitrate solution followed by carbothermal reduction. The composition and morphology of the prepared catalysts were fully assessed by IR, AAS, ICP-MS, XPS, XRD and STEM techniques. This novel bio-genic silver-based catalysts showed excellent activity and remarkable selectivity in the hydrogenation of nitro groups in both aromatic and aliphatic substrates, even in the presence of reactive functionalities like halogens, carbonyls, borate esters or nitriles. Recycling experiments showed that the catalysts can be easily recovered and reused multiple times without significant drop in performance and without requiring re-activation.
Rapid and Quantitative Profiling of Substrate Specificity of ω-Transaminases for Ketones
Han, Sang-Woo,Shin, Jong-Shik
, p. 3287 - 3295 (2019/06/21)
ω-Transaminases (ω-TAs) have gained growing attention owing to their capability for asymmetric synthesis of chiral amines from ketones. Reliable high-throughput activity assay of ω-TAs is essential in carrying out extensive substrate profiling and establishing a robust screening platform. Here we report spectrophotometric and colorimetric methods enabling rapid quantitation of ω-TA activities toward ketones in a 96-well microplate format. The assay methods employ benzylamine, a reactive amino donor for ω-TAs, as a cosubstrate and exploit aldehyde dehydrogenase (ALDH) as a reporter enzyme, leading to formation of benzaldehyde detectable by ALDH owing to concomitant NADH generation. Spectrophotometric substrate profiling of two wild-type ω-TAs of opposite stereoselectivity was carried out at 340 nm with 22 ketones, revealing subtle differences in substrate specificities that were consistent with docking simulation results obtained with cognate amines. Colorimetric readout for naked eye detection of the ω-TA activity was also demonstrated by supplementing the assay mixture with color-developing reagents whose color reaction could be quantified at 580 nm. The colorimetric assay was applied to substrate profiling of an engineered ω-TA for 24 ketones, leading to rapid identification of reactive ketones. The ALDH-based assay is expected to be promising for high-throughput screening of enzyme collections and mutant libraries to fish out the best ω-TA candidate as well as to tailor enzyme properties for efficient amination of a target ketone.
A hydrogenation of acetone ammonia synthesis isopropylamine method (by machine translation)
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Paragraph 0030; 0031; 0032; 0033; 0034; 0035; 0036-0040, (2017/03/14)
The invention discloses a method for hydrogenation of acetone ammonia synthesis isopropylamine method, the reaction feeding before replace the nitrogen in the reactor of the air, and then the preheating of the hydrogen is introduced in the reactor, the catalyst in the reactor temperature is raised to 90 - 180 °C, in the reactor pressure to rise to 0.2 - 1.8 mpa; after preheating into acetone, hydrogen, and ammonia are mixed in the material into the reactor, the catalyst in the presence of 0.2 - 1.8 mpa, 90 - 180 °C hydrogenated ammoniation reaction, to get the crude product, prepared by precipitating the crude product after cooling separator for separating gas and liquid, liquid is rough isopropylamine. The invention make coarse isopropylamine in isopropylamine content is high, acetone conversion rate 100%, isopropylamine selectively in 99.7% or more. (by machine translation)
