88-14-2Relevant articles and documents
Kinetic and mechanistic analysis of oxidation of 2-furoic hydrazide by hexachloroirradate(IV) in a wide pH range
Yao, Haiping,Tian, Hongwu,Xu, Liyao,Xia, Yanqing,Zhou, Li,Liu, Chunli,Shi, Tiesheng
, p. 771 - 777 (2019)
Oxidation of 2-furoic hydrazide (FH) by hexachloroiridate(IV) ([IrCl6]2?) was studied kinetically in a wide pH range in aqueous solution of 1.0?M ionic strength. The oxidation reaction followed well-defined second-order kinetics: ? d[IrCl6 2?]/dt = k′[FH]tot[IrCl6 2?], where [FH]tot denotes the total concentration of FH and k′ stands for the observed second-order rate constants. The established k′–pH profile displays that k′ increases drastically with pH and a plateau region exists between pH 4 and 6. A stoichiometric ratio of Δ[FH]tot/Δ[IrCl6 2?] = 1/4?was revealed by spectrophotometric titrations. 1H NMR spectroscopic studies indicated that FH was cleanly oxidized to 2-furoic acid. The kinetic data suggest a reaction mechanism in which all the three protolysis species of FH react with [IrCl6]2? in parallel, forming the rate-determining steps. Two stabilized hydrazyl radicals are generated in the rate-determining steps, in which a single electron is transferred to [IrCl6]2?. The two hydrazyl radicals react rapidly in consecutive steps requiring 3?mol of Ir(IV) to form 2-furoic acid as the final product. Rate constants of the rate-determining steps were deduced through a simulation of the rate expression to the k′–pH dependency data. Values of these rate constants demonstrate that the three protolysis species of FH have a huge reactivity span, changing by about 109 times toward reduction in [IrCl6]2? and that FH can be readily oxidized in neutral and basic media. Rapid scan spectra and the measured activation parameters suggest that an outer-sphere electron transfer is probably taking place in each of the rate-determining steps. This is the first kinetic study on the oxidation reactions of FH and provides concurrently the protolysis constants of FH (pKa1 = 3.04 ± 0.08 and pKa2 = 11.6 ± 0.1) at 25.0?°C and 1.0?M ionic strength.
High performance of Au/ZTC based catalysts for the selective oxidation of bio-derivative furfural to 2-furoic acid 1
Centi, Gabriele,Cozza, Daniela,Giordano, Girolamo,Giorgianni, Gianfranco,Lanzafame, Paola,Migliori, Massimo,Papanikolaou, Georgia,Perathoner, Siglinda
, (2021)
Furfural is a platform bio-molecule for which is valuable to develop new green upgrading processes in biorefinery. We report here for the first time the high performance of Au/ZTC catalyst for the selective oxidation of furfural to 2-furoic acid, as first step to develop electrodes. The ordered nanostructure and high surface area of BEA structure replica ZTC allows to develop 3D-type electrodes. Au/ZTC catalyst shows higher performance than commercial Vulcan, used as reference conductive carbon in fuel cells. The weak acidity on ZTC avoids decarboxylation and esterification reactions, leading to about 90% of furfural conversion fully selectivity to 2-furoic acid.
Transformation of Thioacids into Carboxylic Acids via a Visible-Light-Promoted Atomic Substitution Process
Fu, Qiang,Liang, Fu-Shun,Lou, Da-Wei,Pan, Gao-Feng,Wang, Rui,Wu, Min,Xie, Kai-Jun
, p. 2020 - 2024 (2022/03/31)
A visible-light-promoted atomic substitution reaction for transforming thiocacids into carboxylic acids with dimethyl sulfoxide (DMSO) as the oxygen source has been developed, affording various alkyl and aryl carboxylic acids in over 90% yields. The atomic substitution process proceeds smoothly through the photochemical reactivity of the formed hydrogen-bonding adduct between thioacids and DMSO. A DMSO-involved proton-coupled electron transfer (PCET) and the simultaneous generation of thiyl and hydroxyl radicals are proposed to be key steps for realizing the transformation.
Cleavage of Carboxylic Esters by Aluminum and Iodine
Sang, Dayong,Yue, Huaxin,Fu, Yang,Tian, Juan
, p. 4254 - 4261 (2021/03/09)
A one-pot procedure for deprotecting carboxylic esters under nonhydrolytic conditions is described. Typical alkyl carboxylates are readily deblocked to the carboxylic acids by the action of aluminum powder and iodine in anhydrous acetonitrile. Cleavage of lactones affords the corresponding ω-iodoalkylcarboxylic acids. Aryl acetylates undergo deacetylation with the participation of the neighboring group. This method enables the selective cleavage of alkyl carboxylic esters in the presence of aryl esters.
Synthesis, biological evaluation and molecular docking studies of indeno [1, 2-c] pyrazol derivatives as inhibitors of mitochondrial malate dehydrogenase 2 (MDH2)
Ahmadi, Farzaneh,Engel, Matthias,Baradarani, Mehdi M.
, (2021/03/15)
Hypoxia inducible factor-1 (HIF-1) is a pivotal transcription factor, which is strongly correlated with the induction of angiogenesis, tumor survival, metastasis, and cell proliferation, making it a pivotal therapeutic target for solid tumor therapeutic agents. Herein, a new series of multi-functional chemical probes were designed including principal groups, viz. adamantyl and indene, at various locations of the parent compound LW6. Molecular docking studies were performed on the designed compounds and their relationship with HIF-1α and malate dehydrogenase 2 (MDH2). Inhibition of MDH2 by our compounds was expected to decrease the NADH level. Indeed, treatment of the breast cancer cell line 4T1 led to a strong reduction of the NADH concentration. The greatest reduction in NADH production in mitochondria was observed with (E)-3-(4-((3r, 5r, 7r)-adamantan-1-yl) phenoxy)-N-(5-(piperidine-1-carbonyl)-1, 4-dihydroindeno [1, 2-c] pyrazol-3-yl) acrylamide (18: IC50 = 59 nM), and has the best inhibitory potential under hypoxic conditions (MCF-7: IC50 = 57 nM). This compound also gave one of the highest docking “higher than the score obtained with LW6 in parallel (?31.63 kcal/mol) in the initial docking runs (PDB Code: 4WLO). Other related compounds with good yields were also synthesized from docking results, and all the synthesized compounds (14, 18, 22, 26, 29, 30) were evaluated in vitro on human adenocarcinoma cell lines.
Preparation method for producing furan ammonium salt by using 2-acetylfuran
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Paragraph 0031-0034; 0046-0049; 0061-0064; 0078-0081; 0093, (2021/06/23)
The invention discloses a preparation method for producing furan ammonium salt by using 2-acetylfuran. The preparation method comprises the following steps: preparation of furanone acid, generation of 2-methoxyamine-2-furanacetic acid through oximation, purification of oximation reaction liquid and ammonification treatment. 2-acetylfuran is used as a raw material, the furan ammonium salt is obtained through oxidation, oximation, extraction and ammonification operation, a compound catalyst is added in the oxidation process, and the reaction speed is further increased through addition of transition metal salt; the transition metal salt and the catalytic promoter are combined with each other, and the catalytic promoter is used for synergistically promoting the catalytic performance of the transition metal salt, so that the conversion rate of furanone acid is further improved.
Au-catalyzed electrochemical oxidation of alcohols using an electrochemical column flow cell
Suga, Tatsuya,Shida, Naoki,Atobe, Mahito
, (2021/02/09)
A novel green system for the electrochemical oxidation of alcohols is demonstrated using a column flow cell. Voltammetric analysis revealed that the oxidation of 1-phenylethanol and benzaldehyde are promoted by using both an Au-electrode and an alkaline medium. To conduct such reaction with a column flow cell, we developed a method to modify a carbon-fiber thread with Au nanoparticles. The column carbon-fiber thread electrode modified with Au nanoparticles showed a high surface area, enabling the efficient electrochemical oxidation of various alcohols.
Hydrogen-Binding-Initiated Activation of O?H Bonds on a Nitrogen-Doped Surface for the Catalytic Oxidation of Biomass Hydroxyl Compounds
Liu, Xin,Luo, Yang,Ma, Hong,Zhang, Shujing,Che, Penghua,Zhang, Meiyun,Gao, Jin,Xu, Jie
, p. 18103 - 18110 (2021/07/14)
Hydrogen binding of molecules on solid surfaces is an attractive interaction that can be used as the driving force for bond activation, material-directed assembly, protein protection, etc. However, the lack of a quantitative characterization method for hydrogen bonds (HBs) on surfaces seriously limits its application. We measured the standard Gibbs free energy change (ΔG0) of on-surface HBs using NMR. The HB-accepting ability of the surface was investigated by comparing ΔG0 values employing the model biomass platform 5-hydroxymethylfurfural on a series of Co-N-C-n catalysts with adjustable electron-rich nitrogen-doped contents. Decreasing ΔG0 improves the HB-accepting ability of the nitrogen-doped surface and promotes the selectively initiated activation of O?H bonds in the oxidation of 5-hydroxymethylfurfural. As a result, the reaction kinetics is accelerated. In addition to the excellent catalytic performance, the turnover frequency (TOF) for this oxidation is much higher than for reported non-noble-metal catalysts.
Cu2O-Catalyzed Conversion of Benzyl Alcohols Into Aromatic Nitriles via the Complete Cleavage of the C≡N Triple Bond in the Cyanide Anion
Liu, Wenbo,Tang, Peichen,Zheng, Yi,Ren, Yun-Lai,Tian, Xinzhe,An, Wankai,Zheng, Xianfu,Guo, Yinggang,Shen, Zhenpeng
, p. 3509 - 3513 (2021/10/04)
Nitrogen transfer from cyanide anion to an aldehyde is emerging as a promising method for the synthesis of aromatic nitriles. However, this method still suffers from a disadvantage that a use of stoichiometric Cu(II) or Cu(I) salts is required to enable the reaction. As we report herein, we overcame this drawback and developed a catalytic method for nitrogen transfer from cyanide anion to an alcohol via the complete cleavage of the C≡N triple bond using phen/Cu2O as the catalyst. The present condition allowed a series of benzyl alcohols to be smoothly converted into aromatic nitriles in moderate to high yields. In addition, the present method could be extended to the conversion of cinnamic alcohol to 3-phenylacrylonitrile.
An Anionic, Chelating C(sp3)/NHC ligand from the Combination of an N-heterobicyclic Carbene and Barbituric Heterocycle
Benaissa, Idir,Gajda, Katarzyna,Vendier, Laure,Lugan, No?l,Kajetanowicz, Anna,Grela, Karol,Michelet, Véronique,César, Vincent,Bastin, Stéphanie
, p. 3223 - 3234 (2021/09/30)
The coordination chemistry of the anionic NHC1-based on an imidazo[1,5-a]pyridin-3-ylidene (IPy) platform substituted at the C5 position by an anionic barbituric heterocycle was studied with d6(Ru(II), Mn(I)) and d8(Pd(II), Rh(I), Ir(I), Au(III)) transition-metal centers. While the anionic barbituric heterocycle is planar in the zwitterionic NHC precursor 1·H, NMR spectroscopic analyses supplemented by X-ray diffraction studies evidenced the chelating behavior of ligand 1-through the carbenic and the malonic carbon atoms in all of the complexes, resulting from a deformation of the lateral barbituric heterocycle. The complexes were obtained by reaction of the free carbene with the appropriate metal precursor, except for the Au(III) complex 10, which was obtained by oxidation of the antecedent gold(I) complex [AuCl(1)]?with PhICl2as an external oxidant. During the course of the process, the kinetic gold(I) intermediate 9 resulting from the oxidation of the malonic carbon of the barbituric moiety was isolated upon crystallization from the reaction mixture. The νCOstretching frequencies recorded for complex [Rh(1)(CO)2] (5) demonstrated the strong donating character of the malonate-C(sp3)/NHC ligand 1-. The ruthenium complex [Ru(1)Cl(p-cymene)] (11) was implemented as a precatalyst in the dehydrogenative synthesis of carboxylic acid derivatives from primary alcohols and exhibited high activities at low catalyst loadings (25-250 ppm) and a large tolerance toward functional groups.
