1825-14-5Relevant academic research and scientific papers
Highly diastereoselective Markovnikov hydration of 3,4-dialkoxy-1-alkenes and 4,5-dialkoxy-2-alkenes via a hydroboration-oxidation process
Jung, Michael E.,Karama, Usama
, p. 7907 - 7910 (1999)
Hydroboration-oxidation of 3,4-dialkoxy- and 3,4,5-trialkoxy-1-alkenes and 4,5-dialkoxy-2-alkenes occurs to give high proportions of the secondary alcohols (Markovnikov hydration) with excellent diastereoselectivity (anti to the allylic alkoxide).
Heterogenized Ru(II) phenanthroline complex for chemoselective hydrogenation of diketones under biphasic aqueous medium
Deshmukh, Amit,Kinage, Anil,Kumar, Rajiv,Meijboom, Reinout
, p. 114 - 120 (2010)
The chemoselective hydrogenation of acetylacetone to 4-hydroxypentan-2-one over immobilized ruthenium phenanthroline metal complexes in amino functionalized MCM-41 in biphasic aqueous reaction medium was investigated. The catalyst was characterized by XRD, TEM, surface analysis, FT-IR and UV-vis to understand the morphology, complex geometry, and XPS such that the oxidation state of the metal complex inside the MCM-41 framework could be understood. The use of water as a solvent, not only gives high activity and selectivity for hydrogenation of acetylacetone, but also gives a path for an environmentally safer process. The optimizations of ligand, metal to ligand ratio, the choice of solvent and other reaction parameters were studied in detail. The heterogeneous catalytic system gave a higher degree of chemoselectivity (99%) towards 4-hydroxypentan-2-one as compared to homogeneous catalyst when hydrogenation was carried out using water as a solvent. The immobilized ruthenium-phenanthroline complex was easily separated and reused.
Stereochemical Studies of the Hydrogenation with an Asymmetrically Modified Raney Nickel Catalyst. The Hydrogenation of Acetylacetone
Tai, Akira,Ito, Kazuhisa,Harada, Tadao
, p. 223 - 227 (1981)
The hydrogenation of acetylacetone (I) over asymmetrically modified Raney nickel (MRNi) proceeded, step by step, as follows: Step 1 Step 2 acetylacetone (I) ------> 4-hydroxy-2-pentanone (III) ------> 2,4-pentanediol (II).It was demonstrated that the optical yield of Step 1 and the diastereomer excess of Step 2 are governed by the ratio of the stereo-differentiating reaction site to the non-stereo-differentiating reaction site on the catalyst.The stereochemistry of each step was also discussed based on the mode of the intermolecular hydrogen bondings between the substrate and tartaric acid adsorbed on the catalyst.RNi modified with a mixture of tartaric acid and NaBr (TA-NaBr-MRNi) gave the best result with respect to both Step 1 and Step 2.
Synthesis and Applications of (Pyridyl)imine Fe(II) Complexes as Catalysts in Transfer Hydrogenation of Ketones
Kumah, Robert T.,Vijayan, Paranthaman,Ojwach, Stephen O.
, p. 344 - 352 (2020/07/25)
Abstract: Chiral (pyridyl)imine Fe(II) complexes, [Fe(L1)3]2+[PF6?]2, (Fe1), [Fe(L2)3]2+[PF6?]2, (Fe2), [Fe(L3)3]2+[PF6?]2 (Fe3), and [Fe(L4)3]2+[PF6?]2 (Fe4) were synthesised by reactions of synthons (S-)-1-phenyl-N-(pyridine-2-yl) ethylidine)ethanamine (L1), (R-)-1-phenyl-N-(pyridine-2-yl) ethylidine) ethanamine (L2), (S)-1-phenyl-N-(pyridine-2-yl methylene) ethanamine (L3) and (S)-1-phenyl-N-(pyridine-2-yl methylene)ethanamine (L4) with the FeCl2 salt. The solid-state structure of complex Fe4 showed that the?Fe atom contains three units of bidentate bound ligand L4 to form a six-coordinate cationic compound. The Fe(II) complexes were evaluated as catalysts in asymmetric transfer hydrogenation of ketones reactions and showed moderate catalytic activities with low enantioselectivity. Catalytic activities of the respective complexes were regulated by the nature of the metal complexes, ketone substrate and reaction conditions. Mercury and sub-stoichiometric poisoning experiments implicate possible formation of both active Fe(0) nanoparticles and Fe(II) homogeneous intermediates. Graphic Abstract: [Figure not available: see fulltext.]
Chemoselective formation of cyclo-aliphatic and cyclo-olefinic 1,3-diolsviapressure hydrogenation of potentially biobased platform molecules using Kn?lker-type catalysts
Alsters, Paul L.,Chou, Khi Chhay,De Wildeman, Stefaan M. A.,Faber, Teresa,Hadavi, Darya,Han, Peiliang,Quaedflieg, Peter J. L. M.,Schwalb Freire, Alfonso J.,Verzijl, Gerard K. M.,van Slagmaat, Christian A. M. R.
supporting information, p. 10102 - 10112 (2021/08/03)
The hydrogenative conversions of the biobased platform molecules 4-hydroxycyclopent-2-enone and cyclopentane-1,3-dione to their corresponding 1,3-diols are established using a pre-activated Kn?lker-type iron catalyst. The catalyst exhibits a high selectivity for ketone reduction, and does not induce dehydration. Moreover, by using different substituents of the ligand, thecis-transratio of the products can be affected substantially. A decent compatibility of this catalytic system with various structurally related substrates is demonstrated.
Method for preparing beta-diol from beta-diketone
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Paragraph 0037; 0048; 0049, (2016/11/24)
The invention relates to a method for preparing beta-diol from beta-diketone. The method is characterized in that beta-diketone contacts and reacts with hydrogen in the presence of a hydrogenation catalyst under fixed bed reaction conditions, the hydrogenation catalyst comprises an active component copper and a carrier, and the hydrogenation catalyst preferably comprises an assistant component selected from VIIIB and IB group elements, the assistant is preferably selected from one or more of Ni, Co and Ag, and the carrier is SiO2. The method adopting a fixed bed hydrogenation technology and using a copper-containing supported catalyst has the advantages of no pollution to environment, mild operating conditions, and suitableness for continuous production.
Method for preparing beta-diol from beta-diketone by hydrogenation
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Paragraph 0041-0044, (2017/02/23)
The invention relates to a method for preparing beta-diol from beta-diketone by hydrogenation. The method comprises the following steps: in the presence of a catalyst and under the fixed-bed hydrotreating reaction condition, enabling beta-diketone to be in contact with hydrogen, so as to obtain beta-diol, wherein the catalyst contains CuO and ZnO, preferably also contains Al2O3, and more preferably also contains alkali metal oxides. According to the method for preparing beta-diol from beta-diketone by hydrogenation, provided by the invention, the technology of continuously producing beta-diol by adopting a fixed bed device is realized, the technology is simple and convenient to operate, the utilization ratio of raw materials and the production efficiency of products are improved, the reaction does not need to be carried out under high pressure, and potential safety hazards are reduced.
A β-diketone fixed bed hydrogenation method for preparing β-diol (by machine translation)
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Paragraph 0038-0039, (2017/02/28)
The invention relates to a β-diketone fixed bed hydrogenation method for preparing β-diol, including in the presence of hydrogenation catalyst under conditions and fixed bed reaction of the β-diketone reaction contact with hydrogen gas; the hydrogenation catalyst comprises active component copper and carrier, wherein in order to weight part, the content of copper is 20-35 parts, carrier is in a content of 60-80 parts. Preferably, the hydrogenation catalyst also includes selected from group IB and VIIIB additive component, more preferably the assistant is selected from Ni, Ag Co and in one or several of, the carrier is SiO 2. The method provided by the present invention which adopts a fixed bed hydrogenation process and the use of copper-containing supported catalyst, no pollution to the environment, mild operating conditions, is suitable for continuous production. (by machine translation)
Method for preparation of beta-diol
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Paragraph 0030-0031, (2017/03/17)
The present invention relates to a method for preparation of a beta-diol from a beta-diketone by hydrogenation, the method comprises contact reaction of the beta-diketone and hydrogen in the presence of a hydrogenation catalyst and under fixed bed reaction conditions, the hydrogenation catalyst is a non-noble metal catalyst, includes a metal component and a carrier, and can be prepared by a conventional method. The method uses a fixed bed hydrogenation process, and is free of environmental pollution, mild in operating conditions, and suitable for continuous production.
Rabbit 3-hydroxyhexobarbital dehydrogenase is a NADPH-preferring reductase with broad substrate specificity for ketosteroids, prostaglandin D2, and other endogenous and xenobiotic carbonyl compounds
Endo, Satoshi,Matsunaga, Toshiyuki,Matsumoto, Atsuko,Arai, Yuki,Ohno, Satoshi,El-Kabbani, Ossama,Tajima, Kazuo,Bunai, Yasuo,Yamano, Shigeru,Hara, Akira,Kitade, Yukio
, p. 1366 - 1375 (2013/11/19)
3-Hydroxyhexobarbital dehydrogenase (3HBD) catalyzes NAD(P) +-linked oxidation of 3-hydroxyhexobarbital into 3-oxohexobarbital. The enzyme has been thought to act as a dehydrogenase for xenobiotic alcohols and some hydroxysteroids, but its physiological function remains unknown. We have purified rabbit 3HBD, isolated its cDNA, and examined its specificity for coenzymes and substrates, reaction directionality and tissue distribution. 3HBD is a member (AKR1C29) of the aldo-keto reductase (AKR) superfamily, and exhibited high preference for NADP(H) over NAD(H) at a physiological pH of 7.4. In the NADPH-linked reduction, 3HBD showed broad substrate specificity for a variety of quinones, ketones and aldehydes, including 3-, 17- and 20-ketosteroids and prostaglandin D2, which were converted to 3α-, 17β- and 20α-hydroxysteroids and 9α,11β- prostaglandin F2, respectively. Especially, α-diketones (such as isatin and diacetyl) and lipid peroxidation-derived aldehydes (such as 4-oxo- and 4-hydroxy-2-nonenals) were excellent substrates showing low Km values (0.1-5.9 μM). In 3HBD-overexpressed cells, 3-oxohexobarbital and 5β-androstan-3α-ol-17-one were metabolized into 3-hydroxyhexobarbital and 5β-androstane-3α,17β-diol, respectively, but the reverse reactions did not proceed. The overexpression of the enzyme in the cells decreased the cytotoxicity of 4-oxo-2-nonenal. The mRNA for 3HBD was ubiquitously expressed in rabbit tissues. The results suggest that 3HBD is an NADPH-preferring reductase, and plays roles in the metabolisms of steroids, prostaglandin D2, carbohydrates and xenobiotics, as well as a defense system, protecting against reactive carbonyl compounds.
