109-88-6Relevant articles and documents
Tri-, tetra-, and hexanuclear mixed-valence molybdenum clusters: Structural diversity and catalysis of acetylene hydrogenation
Kuznetsov, Denis A.,Bazhenova, Tamara A.,Fedyanin, Ivan V.,Martynenko, Vyacheslav M.,Shestakov, Alexander F.,Petrova, Galina N.,Komarova, Natal'Ya S.
, p. 16309 - 16316 (2016)
A series of novel cluster compounds comprising molybdenum in a low valence state was synthesized by means of a disproportionation of the dimeric compound [Mo+42Cl4(OCH3)4(CH3OH)2] (1). The reaction of 1 with CH3OH leads to the disproportionation of Mo+4 yielding an unusual mixed-valence cluster [Mo+3.54Cl4O2(OCH3)6(CH3OH)4] (2). By exploring this synthetic approach further, tri-{[Mo3Cl3(OCH3)7(CH3OH)3] (3)}, tetra-{[Mo4Cl4(OCH3)10(CH3OH)2] (4), [Mo4Cl3O(OCH3)9(CH3OH)3] (5), [Mo4Cl2(OCH3)12(CH3OH)2] (6)}, and hexanuclear {[Mo6Cl4O6(OCH3)10(CH3OH)2] (7)} molybdenum alkoxides were synthesized by the reaction of 1 with methanol and stoichiometric amounts of magnesium methoxide, thus providing a general facile access to the polynuclear methoxide complexes of a low-valence molybdenum. Due to the feasibility to adopt multiple oxidation states in a reversible manner and the documented competence of molybdenum alkoxide compounds to catalyze the reduction of inert molecules, including N2, the synthesized compounds were expected to function as catalysts of small molecule substrates reduction/hydrogenation. Accordingly, the reduction of acetylene (C2H2) to an ethylene (C2H4) and ethane (C2H6) mixture, in methanol (with water additives) serving as a reaction medium and a proton donor, and using sodium or europium amalgams as reducing agents, was performed in the presence of 2. Preliminary kinetic studies evidently point to a catalytic function of molybdenum species derived from 2, thus establishing the observed reactivity as a rare example of non-precious metal-catalyzed acetylene hydrogenation, providing, in addition, a convenient model for further mechanistic studies.
An Acetylacetonate or a Pyrazole? Both! 3-(3,5-Dimethyl-pyrazol-4-yl)pentane-2,4-dione as a Ditopic Ligand
Guo, Qianqian,Englert, Ulli
, p. 5127 - 5135 (2016)
The alternative coordination sites of 3-(3,5-dimethyl-pyrazol-4-yl)pentane-2,4-dione (H2acacPz) differ with respect to Pearson hardness. The softer, heterocyclic moiety was used as N donor toward Zn(II) and Ag(I); it yielded a tetrahedral, neutral Zn complex in the former and a monocationic, linear bis(ligand) Ag complex in the latter case. After deprotonation with silver benzoate, the pyrazolyl ring may act as a monoanionic N,N′-bridge between neighboring cations in a hexanuclear Ag aggregate; in addition to ligand-supported Ag···Ag distances of ca. 3.2 ?, these aggregates feature ligand-unsupported argentophilic interactions of ca. 2.9 ?. With stronger bases and in the presence of oxophilic Mg cations, the harder hydroxyketone part of the H2acacPz ligand may be deprotonated to a chelating acetylacetonate. The resulting bis(ligand) Mg complex has been used as starting compound for a bimetallic derivative: the ditopic ligand allows coordinating cadmium acetate to its dangling N donor site, thus, bridging divalent Mg and Cd in a bimetallic three-dimensional coordination network of pts topology.
Upgrading of furfural to biofuel precursors: Via aldol condensation with acetone over magnesium hydroxide fluorides MgF2- x(OH)x
Xu, Minrui,Célérier, Stéphane,Comparot, Jean-Dominique,Rousseau, Julie,Corbet, Matthieu,Richard, Frédéric,Clacens, Jean-Marc
, p. 5793 - 5802 (2019)
Wastes from lignocellulosic materials, especially hemicellulose, are extremely promising resources to produce fuels from renewable raw materials. Furfural, resulting from the depolymerization of hemicellulose, is often considered as an extremely interesting platform molecule. Particularly, new biofuels containing molecules with 8 and 13 carbon atoms can be produced from aldol condensation of furfural and acetone followed by a deoxygenation reaction. In this work, several magnesium hydroxide fluorides MgF2-x(OH)x were prepared by a sol-gel method with various F/Mg ratios (0 to 2) at 100 °C. All solid samples were fully characterized by several techniques (nitrogen adsorption-desorption, TEM, IR, XRD and ICP). MgF2-x(OH)x were mainly composed of an intimate mixture of MgF2 and Mg(OH)2-x(OCH3)x and exhibited both acid-base properties and high surface areas. From CO2 adsorption experiments, a basicity scale corresponding to basic sites with moderate strength was established: MgF1.5(OH)0.5 > MgF(OH) ～ MgF1.75(OH)0.25 > MgF0.5(OH)1.5 > Mg(OH)2 ? MgF2. It was proposed that the presence of fluorine allowed stabilization of the basic sites with moderate strength at ambient atmosphere. The aldol condensation of furfural and acetone was carried out under mild reaction conditions (50 °C, Patm) over MgF2-x(OH)x. These catalysts were involved in this reaction without using a classical activation step for basic solid catalysts, which constitutes a major advantage of energy conservation and thus, economic efficiency. The solid with a F/Mg ratio equal to 1.5 (MgF1.5(OH)0.5) exhibited the highest activity, the furanic dimer (1,5-di(furan-2-yl)penta-1,4-dien-3-one) being the main product. A good correlation between the catalytic activity and the basicity scale was highlighted. Based on these results, the nature of active sites was proposed: a combination of a Lewis acid site (coordinatively unsaturated metal site) in the vicinity of a basic site (hydroxyl groups of Mg(OH)2-x(OCH3)x). The effect of the furfural/acetone ratio on the catalytic properties of MgF1.5(OH)0.5 was also investigated.
Synthesis of benzyl/allyl alkyl ethers from corresponding magnesium alkoxides
Lin, Ji-Mao,Li, Hui-Hui,Zhou, Ai-Min
, p. 5159 - 5160 (1996)
In the presence of iodine, alcohols react with magnesium to produce magnesium alkoxides which are then treated with benzyl chloride or allyl bromide to produce benzyl alkyl ethers or allyl alkyl ethers.
Synthesis and Tubulin Binding of Novel C-10 Analogues of Colchicine
Staretz, Marianne E.,Hastie, Susan Bane
, p. 758 - 764 (1993)
A series of novel C-10 derivatives of colchicine have been prepared and evaluated for inhibition of in vitro microtubule assembly and of colchicine binding to tubulin.The C-10 substituent of colchicine was replaced by halogens, alkyl and alkoxy groups, and hydrogen.Many of these compounds are available by nucleophilic substitution of 10-fluoro-10-demethoxycolchicine (9) without concomitant formation of ring contraction products.Compound 9 is prepared by reaction of (diethylamino)sulfur trifluoride with colchicine.Unlike most reactions of colchicine, the colchicine rather than the isocolchicine regioisomer is the predominant product of this reaction.It was found that modification of the C-10 substituent of colchicine had a relatively minor effect on the potency of the colchicinoids.The electronic nature of the substituent had no significant effect on the efficacy of the compound, indicating that hydrogen bonding or polar interactions between the C-10 substituent of colchicinoids and an amino acid in the colchicine binding site on tubulin are not present in the colchicine-tubulin complex.A decrease in activity was observed with increasing length of the alkyl chain bonded to the C-10 position, but potency was less affected when the alkyl groups were positioned in close proximity to the C-10 carbon of the tropone ring.It is concluded that the steric rather than the electronic properties of the C-10 substituent are the predominant determinants of activity in this series.
Alkoxy metal powder as well as preparation method and application thereof
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Paragraph 0079-0080, (2019/12/02)
The invention relates to a preparation method and an application of alkoxy metal powder, which are applied to preparation of an alkoxy metal carrier of an olefin polymerization catalyst. The alkoxy metal carrier comprises the following components: metal halide, sodium alcoholate or potassium alcoholate, or a solvent. The molar ratio of the components for preparing the alkoxy metal compound is as follows: metal halide: sodium alcoholate or potassium alcoholate = 1:(0.001-30); wherein the metal halide is a metal chloride, a metal bromide, a metal fluoride or a metal iodide; the metal is a main group metal, a sub-group metal or a VIII group metal. The catalyst prepared from the carrier is used for preparing an olefin polymerization catalyst, and has the advantages of high catalyst activity, good hydrogen regulation performance, good copolymerization performance, low polymer powder content, low wax content and good particle morphology; the catalyst is used for ethylene homopolymerization,ethylene and alpha-olefin copolymerization or ethylene and polar alkene monomer copolymerization, propylene homopolymerization, propylene and alpha-olefin copolymerization, or propylene and polar alkene monomer copolymerization.
Stereoselective synthesis of α-methyl and α-alkyl ketones from esters and alkenes: Via cyclopropanol intermediates
Barysevich, Maryia V.,Kazlova, Volha V.,Kukel, Aliaksandr G.,Liubina, Aliaksandra I.,Hurski, Alaksiej L.,Zhabinskii, Vladimir N.,Khripach, Vladimir A.
supporting information, p. 2800 - 2803 (2018/03/21)
Alkenes bearing a stereocenter in the allylic position were found to undergo Kulinkovich hydroxycyclopropanation with good diastereoselectivity. For the isomerization of the resulting cyclopropanols to diastereomerically enriched α-methyl ketones, a new mild regioselective method has been developed. A sequence of stereoselective cyclopropanation and cyclopropanol ring opening was successfully employed for the construction of the C20 stereocenter in steroids.
Cobalt Oxide Materials for Oxygen Evolution Catalysis via Single-Source Precursor Chemistry
Kuznetsov, Denis A.,Konev, Dmitry V.,Sokolov, Sergey A.,Fedyanin, Ivan V.
, p. 13890 - 13896 (2018/09/14)
The utilization of metal alkoxides as single-source precursors for (mixed-)oxide materials offers remarkable benefits, such as the possibility to precisely control the metal ratio in the resulting material, highly homogeneous distribution of the elements in the film, and the low temperatures required for film processing. Herein we report on the isolation and characterization of the bimetallic Co-Mo alkoxide [Co3Mo4O10(OCH3)10(dmf)4] (Co3Mo4; dmf=N,N-dimethylformamide), which was prepared by the anion metathesis reaction of the corresponding metal chlorides. The Co-Mo alkoxide was explored as a well-defined precursor of cobalt oxide catalysts for the oxygen evolution reaction (OER) in alkaline electrolyte MOH. The catalysts demonstrated excellent activity in the OER, manifested in low onset potentials and Tafel slopes and superb stability under the operating conditions both in alkaline and nearly neutral media. It was observed that the nature of the metal cation of the alkaline electrolyte MOH (M+=Li+, Na+, K+, Cs+) greatly affected the catalytic performance of the material. We propose that the positive effect of larger metal cations on the film activity in the OER could be explained by the higher hydration enthalpies of larger ions and enhanced mass transport within a larger interlayer space between the [CoO2]δ?∞ sheets of the in situ formed binary oxides. It may be deduced that this trend is universal and may be extended to other types of metal oxides forming layered structures during the OER.
BIOSYNTHESIS OF CANNABINOID PRODRUGS AND THEIR USE AS THERAPEUTIC AGENTS
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Paragraph 0199, (2017/11/07)
The present invention provides methods for producing cannabinoid prodrugs. Also described are pharmaceuticals acceptable compositions of the prodrugs and a system for the large-scale production of the prodrugs.
Polyfluorinated salicylic acid derivatives as analogs of known drugs: Synthesis, molecular docking and biological evaluation
Shchegol'kov,Trefilova,Borisevich,Shchur,Ljushina,Khursan,Burgart, Ya.V.,Solodnikov, S.Yu.,Saloutin,Markova,Maslova,Krasnykh
, p. 91 - 99 (2016/12/22)
We have developed the convenient methods for synthesis of polyfluorosalicylic acids and their derivatives. For the first time the biological properties of polyfluorosalicylates were investigated in vitro (permeability through the biological membranes, COX-1 inhibitory action) and in vivo (anti-inflammatory, analgesic activities, acute toxicity). Molecular docking of polyfluorinated salicylates confirmed in vitro and in vivo experiments.
