- H2SO4/SiO2 as an efficient catalyst for the preparation of phenylhydrazones and 2,4-dinitrophenylhydrazones under solvent-free conditions
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H2SO4 mixed with silica gel (1:1) by weight produces a white powder which is an effective catalyst for the conversion of carbonyl compounds to their corresponding phenylhydrazones and 2,4-dintrophenylhydrazones under solvent-free conditions.
- Kiasat, Ali Reza,Kazemi, Foad,Nourbakhsh, Kazem
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- Synthesis and Antimicrobial Resistant Modulatory Activity of 2,4-Dinitrophenylhydrazone Derivatives as Agents against Some ESKAPE Human Pathogens
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A library of six novel phenylhydrazones were synthesized and evaluated for their in vitro antimicrobial and resistance modulating activity against a panel of Gram-positive, Gram-negative, and fungal species. The compounds were produced in good yields of 6
- Ade, Alberta,Amengor, Cedric D. K.,Ayensu, Isaac,Boakye, Yaw Duah,Brobbey, Abena,Harley, Benjamin K.
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- Noncovalent interaction stabilizes the 2,4-Dinitrophenylhydrazone Derivatives over g-C3N4 surface to enhance optical properties: Synthesis, characterization, and DFT investigation
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Immobilization of organic compounds on semiconductor surface was recently exploited to enhance the semiconductor light absorption and photocatalytic performance. Here, synthesis of 2,4-Dinitrophenylhydrazone-benzaldehyde (DPHH), 2,4-Dinitrophenylhydrazone
- Alotaibi, Mohammed T.
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- A small molecule that mimics the metabolic activity of copper-containing amine oxidases (CuAOs) toward physiological mono- and polyamines
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Primary aliphatic biogenic amines have been successfully oxidized using a quinonoid species that mimics the metabolic activity of copper-containing amine oxidase (CuAO) enzymes. Especially, high catalytic performances were observed with aminoacetone, a threonine catabolite, and methylamine, a metabolite of adrenaline, and with the primary amino groups of putrescine and spermidine which are both decarboxylation products of ornithine and S-adenosyl-methionine. Furthermore, contrary to flavine adenine dinucleotide (FAD)-dependent amine oxidase enzymes, no activity was found toward secondary and tertiary amines.
- Largeron, Martine,Fleury, Maurice-Bernard,Strolin Benedetti, Margherita
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- Synthesis and properties of 4,9-methanoundecafulvenes and their transformation to 3-substituted 7,12-methanocycloundeca[4,5]furo[2,3-d] pyrimidine-2,4(1H,3H)-diones: Photo-induced autorecycling oxidizing reaction toward amines
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The synthesis and properties of 4,9-methanoundecafulvene [5-(4,9-methanocycloundeca-2′,4′,6′,8′, 10′-pentaenylidene)pyrimidine-2,4,6(1,3,5H)-trione] derivatives 8a,b were studied. Their structural characteristics were investigated on the basis of the 1H and 13C NMR and UV-vis spectra. The rotational barrier (ΔG?) around the exocyclic double bond of 8a was found to be 12.55 kcal mol-1 by the variable temperature 1H NMR measurement. The electrochemical properties of 8a,b were also studied by CV measurement. Furthermore, the transformation of 8a,b to 3-substituted 7,12-methanocycloundeca[4,5]furo[2,3-d]pyrimidine-2,4(1H,3H)-diones 16a,b was accomplished by oxidative cyclization using DDQ and subsequent ring-opening and ring-closure. The structural details and chemical properties of 16a,b were clarified. Reaction of 16a with deuteride afforded C13-adduct 19 as the single product, and thus, the methano-bridge controls the nucleophilic attack to prefer endo-selectivity. The photo-induced oxidation reaction of 16a and a vinylogous compound, 3-methylcyclohepta[4,5]furo[2,3-d]pyrimidine-2,4(3H)-dione 2a, toward some amines under aerobic conditions were carried out to give the corresponding imines (isolated by converting to the corresponding 2,4-dinitrophenylhydrazones) with the recycling number of 6.1-64.0 (for 16a) and 2.7-17.2 (for 2a), respectively.
- Naya, Shin-Ichi,Yamaguchi, Yohei,Nitta, Makoto
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- Benzaldehyde 2,4-dinitrophenyl-hydrazone
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Crystals of the title compound, C13H10N4O4, were obtained from a condensation reaction of benzaldehyde and 2,4-dinitrophenylhydrazine. The molecule assumes an approximately planar E configuration. Within the din
- Shan, Shang,Xu, Duan-Jun,Hung, Chen-Hsiung,Wu, Jing-Yun,Chiang, Michael Y.
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- Preparation, structure, and oxidative reactivity of (dichloroiodo)pyridines: Recyclable hypervalent iodine reagents
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New pyridine-based hypervalent iodine reagents, (dichloroiodo)pyridines, were prepared by chlorination of 2-, 3-, or 4-iodopyridines with NaOCl-HCl at room temperature. Structures of 2-(dichloroiodo)pyridine and 2-(dichloroiodo)-3-propoxypyridine were established by X-ray crystallography. The new (dichloroiodo)pyridines can be used as efficient reagents for oxidation of alcohols to carbonyl compounds and also as chlorinating reagents. The reduced form of the reagents such as 2-iodo-3-propoxypyridine, can be recovered from the reaction mixture in good yields by an acid-base liquid-liquid biphasic protocol.
- Yoshimura, Akira,Nguyen, Khiem C.,Nemykin, Victor N.,Zhdankin, Viktor V.
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- Kinetics and mechanism of oxidation of alcohols
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This paper describes the kinetics and mechanism of oxidation of several monohydric alcohols to the corresponding aldehydes and ketones by bis(quinuclidine)bromine(I) bromide in the presence of pyridinium trifluoroacetate. All evidence from the thermodynamic parameters, deuterium kinetic isotope effect, and Hammett reaction constants supports a two-step mechanism and suggests that the transfer of hydride ion from the substrate to the oxidant is the rate-determining step.
- Laila, Abdulhameed
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- Ring transformation of cyclohepta[b]pyrimido[5,4-d]furan-8(7H),10(9H)- dionylium ion to the corresponding pyrrole derivatives via troponeimine intermediates: Photo-induced autorecycling oxidizing reactions of some amines
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Ring transformation of 7,9-dimethylcyclohepta[b]pyrimido[5,4-d]furan- 8(7H),10(9H)-dionylium tetrafluoroborate 4+·BF 4- to 7,9-dimethylcyclohepta[b]pyrimido[5,4-d]pyrrrole- 8(7H),10(9H)-dionylium tetrafluoroborate 6a-d+·BF 4- consists of the reaction of 4+· BF4- with amines and subsequent exchange of the counter-ion using aq. HBF4. Reactions of 4+·BF 4- with aniline and 4-substituted anilines afforded the corresponding pyrrole derivatives 6a-c+·BF4 - directly in good yields. On the other hand, reaction of 4 +·BF4- with benzylamine gave the troponeimine intermediate 9, which was not converted to 6d+· BF4- and reverted to 4+·BF 4- by adding HBF4; however, it was converted to 6d+·BF4- upon treatment with (COCl)2 or SOCl2, followed by exchange of the counter-ion. In a search for the characteristics of 9, inspection and comparison of the X-ray crystal analyses, NMR and UV-vis spectra, and CV measurement of 9 and N,N-disubstituted troponeimine derivatives 12 were carried out to suggest the remarkable structure of 12 having ionic C-O bonding between the imine-carbon atom and the oxygen atom of the barbituric acid moiety in the solid state. Thus, characteristics of 9 were ascribed to the sterically hindered and favorable conformation of N-protonated troponeimine intermediates. Furthermore, novel photo-induced oxidation reactions of a series of 4+·BF 4-, 5+·BF4-, and 6a,e+·BF4- towards some amines under aerobic conditions were carried out to give the corresponding imines in 455-8362% yields [based on compounds 4+, 5+, and 6a,e +], suggesting the oxidation reaction occurs in an autorecycling process. Mechanistic aspects of the amine-oxidation reaction are also postulated.
- Naya, Shin-Ichi,Nitta, Makoto
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- Highly efficient RuCl3-catalyzed disproportionation of (diacetoxyiodo)benzene to iodylbenzene and iodobenzene; leading to the efficient oxidation of alcohols to carbonyl compounds
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(Diacetoxyiodo)benzene (DIB) selectively oxidizes primary and secondary alcohols to the respective carbonyl compounds in the presence of RuCl3 (0.8-1.0 mol %) at room temperature in aqueous acetonitrile. This reaction proceeds via an initial instantaneous Ru-catalyzed disproportionation of DIB to iodobenzene and iodylbenzene with the latter acting as the actual stoichiometric oxidant toward alcohols.
- Yusubov, Mekhman S.,Chi, Ki-Whan,Park, Joo Yeon,Karimov, Rashad,Zhdankin, Viktor V.
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- Novel Synthesis and Properties of 1,6-Methanocycloundeca[b]pyrimido[5,4-d]pyrrole-12,14-dione Derivatives: Autorecycling Oxidation of Some Amines and Alcohols
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Novel 1,6-methanocycloundeca[b]pyrimido[5,4-d]pyrrole-12,14-dione derivatives 6a,b and 7a-c were synthesized in moderate to good yields by the enamine alkylation and dehydrating condensation reactions of 11-chloro-3,8-methano [11] annulenone (8) with 6-amino-3-substituted uracil derivatives and subsequent elimination of HCl. The 1H NMR spectra clarified that compounds 6a,b and 7a-c are aromatic molecules having a diatropic π-system, which is suggested by the chemical shifts of the bridge methylene protons and peripheral protons. The electrochemical reduction exhibited more positive reduction potentials as compared with those of the vinylogous compounds of cyclohepta-[b]pyrimido[5,4-d]pyrrole derivatives. In a search for the oxidizing function of 6a,b and 7a-c, compounds 6a and 7b were demonstrated to oxidize benzylamines, cyclohexylamine, and benzyl alcohol to give the corresponding carbonyl compounds in more than 100% yield under aerobic and photoirradiation conditions, while only benzylamine was oxidized under aerobic and thermal conditions at 100 °C. Thus, compounds 6a and 7b oxidize amines and alcohols in an autorecyling process, and the efficiency is higher under photoirradiation as compared with the thermal process, suggesting the oxidation reaction probably proceeds via electron transfer from amine and alcohol to the excited and ground states of compounds 6a and 7b.
- Mitsumoto, Yuhki,Nitta, Makoto
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- A new class of functionalized calix[4]arenes as neutral receptors for colorimetric detection of fluoride ions
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A new class of functionalized calix[4]arenes have been synthesized and evaluated for colorimetric detection of fluoride ions. The molecular receptor 4b selectively recognizes fluoride ions via H-bonds and subsequent deprotonation to elicit a distinct colo
- Chawla, Har Mohindra,Shrivastava, Rahul,Sahu, Satya Narayan
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- Nitric oxide reacts with methoxide
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(Chemical Equation Presented) Despite over a century of reports to the contrary, sodium methoxide has been found to react with nitric oxide (NO). The reaction, whose final organic product is sodium formate, is postulated to occur via an intermediate O-bound diazeniumdiolate [CH3O-N(O)=NO -] that decomposes to formaldehyde and nitrous oxide. Sodium formate forms from the aldehyde via a Cannizzaro reaction. Carboxylate salts have similarly been obtained by exposing sodium benzylate and sodium neopentoxide to NO in dioxane solution. Accordingly, sodium trimethylsilanoate should be considered as a substitute for sodium methoxide as the base used to accomplish the replacement of active hydrogens by the diazeniumdiolate functional group via the Traube reaction.
- DeRosa, Frank,Keefer, Larry K.,Hrabie, Joseph A.
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- Oxidative deamination of emixustat by human vascular adhesion protein-1/semicarbazide-sensitive amine oxidase
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Emixustat potently inhibits the visual cycle isomerase retinal pigment epithelium protein 65 (RPE65) to reduce the accumulation of toxic bisretinoid by-products that lead to various retinopathies. Orally administered emixustat is cleared rapidly from the
- Reid, Michael J.,Eyre, Russell,Podoll, Terry
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p. 504 - 515
(2019/05/10)
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- Selective ligand-free cobalt-catalysed reduction of esters to aldehydes or alcohols
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Cobalt(ii) salts combined with NaBHEt3 and eventually a base catalyse efficiently and selectively the reduction of esters to aldehydes or alcohols through hydrosilylation by using phenylsilane. Catalyst characterisation by XRD, XPS, TEM and STEM analyses indicates the materials were partially crystalline with the presence of cobalt nanoparticles. Control experiments suggested low valent Co(0) was the active catalytic species involved.
- Rysak, Vincent,Descamps-Mandine, Armel,Simon, Pardis,Blanchard, Florent,Burylo, Laurence,Trentesaux, Martine,Vandewalle, Maxence,Collière, Vincent,Agbossou-Niedercorn, Francine,Michon, Christophe
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p. 3504 - 3512
(2018/07/29)
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- Correlation analysis of reactivity in the oxidation of substituted benzyl alcohols by benzimidazolium dichromate - A kinetic and mechanistic aspects
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The oxidation of a number of para- and meta-substituted benzyl alcohols by benzimidazolium dichromate (BIDC), in dimethyl sulphoxide, leads to the formation of the corresponding benzaldehydes. The reaction is first order with respect to each BIDC and alcohol. The reaction is catalyzed by hydrogen ions and the dependence has the form kobs = a + b[H+]. The oxidation of [1,1-2H2]benzyl alcohol exhibited the presence of a substantial kinetic isotope effect. The rates of the oxidation of meta-substituted benzyl alcohols correlated best with Taft's σ1 and σR0 constants. The para-substituted compounds exhibited excellent correlation with σ1 and σRBA values. The polar reaction constants are negative. The rate of oxidation of benzyl alcohol was determined in nineteen organic solvents. An analysis of the solvent effect by multiparametric equations indicated the greater importance of the cation-solvating power of the solvents. Suitable mechanisms have been discussed.
- Kumar, Pravesh,Panday, Dinesh,Kothari, Seema
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p. 1207 - 1215
(2020/06/27)
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- One-pot two-step conversion of aromatic carboxylic acids and esters to aromatic aldehydes via indium-catalyzed reductive thioacetalization and desulfurization
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Described herein is that a new approach to a one-pot two-step conversion of aromatic carboxylic acids/esters to aromatic aldehydes, in which indium(III) iodide effectively catalyzes both the first reductive thioacetalization of carboxylic acids and a subsequent desulfurization of the in-situ formed thioacetal intermediates leading to aldehydes.
- Sakai, Norio,Minato, Kohei,Ogiwara, Yohei
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supporting information
p. 4563 - 4567
(2017/11/03)
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- Synthesis and antifungal activity of diaryl hydrazones from 2,4-dinitrophenylhydrazine
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A new series of diarylhydrazones derived from 2,4-dinitrophenylhydrazine were synthesized via condensation with aromatic aldehydes whose structures have been determined by mass spectrometry, infrared spectroscopy, and nuclear magnetic resonance spectra. Y
- Ortiz, Sergio,Nelson, Ronald,Kesternich, Víctor,Pérez-Fehrmann, Marcia,Christen, Philippe,Marcourt, Laurence
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p. 3081 - 3084
(2016/11/17)
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- Selective Hydrosilylation of Esters to Aldehydes Catalysed by Iridium(III) Metallacycles through Trapping of Transient Silyl Cations
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The combination of an iridium(III) metallacycle and 1,3,5-trimethoxybenzene catalyses rapidly and selectively the reduction of esters to aldehydes at room temperature with high yields through hydrosilylation followed by hydrolysis. The ester reduction involves the trapping of transient silyl cations by the 1,3,5-trimethoxybenzene co-catalyst, supposedly by formation of an arenium intermediate whose role was addressed by DFT calculations.
- Corre, Yann,Rysak, Vincent,Capet, Frédéric,Djukic, Jean-Pierre,Agbossou-Niedercorn, Francine,Michon, Christophe
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supporting information
p. 14036 - 14041
(2016/09/21)
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- Synthesis, spectral investigation of Ni(II) schiff base complexes: Antimicrobial activities and catalytic oxidation of alcohols
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Air stable Ni(II) Schiff base complexes viz. [Ni(L1)(PPh3)] and [Ni(L2)(PPh3)] [where L1 and L2 are dianions of Schiff base ligands, respectively] have been synthesized and characterized by analytical and spectral (electronic, FT-IR, 1H, 13C and 31P NMR) methods. The assignment of all the aromatic carbon-hydrogen resonances is made on the basis of 1H-13C HSQC spectrum of the complexes. The Schiff base ligands behave as a bibasic tridentate ligands and bonded through ONO and ONS mode. A square planar structure has been proposed on the basis of spectral data. Novel Ni(II) Schiff base complexes exhibited good antimicrobial activity towards the strains Staphylococcus epidermidis and Escherichia coli. Thermal and air stability of the complexes offer the advantage of oxidation of alcohols.
- Madaselvi,Padma Priya,Jeyaraj,Arun Paul,Kalaivani,Shahul Meeran,Arunachalam
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p. 1682 - 1686
(2016/07/06)
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- A spectrophotometric assay for monoamine oxidase activity with 2, 4-dinitrophenylhydrazine as a derivatized reagent
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A simple, rapid and reliable spectrophotometry was developed to determine monoamine oxidase (MAO). In this study, 2,4-dinitrophenylhydrazine (DNPH), a classic derivatizing reagent, was used to detect MAO-dependent aldehyde production; and traditional DNPH
- Huang, Guili,Zhu, Fei,Chen, Yuhang,Chen, Shiqiang,Liu, Zhonghong,Li, Xin,Gan, Linlin,Zhang, Li,Yu, Yu
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- An efficient partial reduction of α,β-unsaturated esters using DIBAL-H in flow
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The partial reduction of α,β-unsaturated esters and benzoate derivatives to form the corresponding aldehydes was achieved using a flow reactor system within 1 s at a high flow rate (18 mL min-1) under cryogenic conditions (-97°C). Commercially available diisobutylaluminium hydride (DIBAL-H) was used as the reductant. The desired enals and benzaldehyde derivatives, except for 4-methoxycinnamate and 4-methoxybenzoate, were formed selectively and redox economically in moderate to high yields.
- Yoshida, Masahito,Otaka, Hiroyuki,Doi, Takayuki
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p. 6010 - 6016
(2015/03/30)
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- Microwave-assisted reduction of F-BODIPYs and dipyrrins to generate dipyrromethanes
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The reduction of BODIPYs and dipyrrins to dipyrromethanes, via a reaction involving ethylene glycol and sodium methoxide, is reported. When benzyl alcohol is used in place of ethylene glycol, the addition of 2,4-dinitrophenylhydrazine to the reaction mixture after microwave irradiation results in the production of 1-benzylidene-2-(2,4-dinitrophenyl)hydrazone, indicating concomitant production of aldehyde alongside the dipyrromethane.
- Melanson, Jennifer A.,Smithen, Deborah A.,Cameron, T. Stanley,Thompson, Alison
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p. 688 - 694
(2014/08/18)
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- Oxidized single-walled carbon nanotubes (swcns-cooh) as a new catalyst for the protection of carbonyl groups as hydrazones
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Nano-materials are considered as suitable heterogeneous catalysts for many organic reactions. Herein oxidized carbon nanotube (SWCNTs-COOH) has been reported as a heterogeneous catalyst, for protection of carbonyl groups as hydrazones in EtOH at 80 C. The reactions proceed smoothly with good to excellent yields, and the SWCNTs-COOH used can be recycled.
- Borazjani, Maryam Kiani,Safaei, Hamid Reza,Panahandeh, Majid,Kiani, Ali Reza,Kiani, Masoumeh,Mofarahi, Masoud
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p. 279 - 281
(2013/12/04)
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- 2-Iodoxybenzoic acid organosulfonates: Preparation, X-ray structure and reactivity of new, powerful hypervalent iodine(v) oxidants
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New powerful hypervalent iodine(v) oxidants, tosylate and mesylate derivatives of 2-iodoxybenzoic acid (IBX), were prepared by the reaction of IBX with the corresponding sulfonic acids. Single crystal X-ray crystallography of the diacetate derivative of IBX-tosylate revealed an unusual heptacoordinated iodine geometry without any significant intermolecular secondary interactions.
- Yusubov, Mekhman S.,Svitich, Dmitrii Yu.,Yoshimura, Akira,Nemykin, Victor N.,Zhdankin, Viktor V.
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supporting information
p. 11269 - 11271
(2013/12/04)
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- Choice of a suitable hetero-aromatic nitrogen base as promoter for chromic acid oxidation of dl-mandelic acid in aqueous media at room temperature
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Chromic acid oxidation of dl-mandelic acid in the presence and absence of different promoters has been studied in aqueous media under the kinetic conditions [mandelic acid]T a‰ [Cr(VI)]T and [promoter]T a‰ [Cr(VI)]T/
- Saha, Rumpa,Ghosh, Sumanta K.,Ghosh, Aniruddha,Saha, Indrajit,Mukherjee, Kakali,Basu, Ankita,Saha, Bidyut
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p. 631 - 643
(2013/07/27)
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- Aniline mediated oxidative C-C bond cleavage of α-alkoxy aldehydes in air and a model reaction for the synthesis of α-(d)-amino acid derivatives
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A metal-free and 4-methyl aniline mediated method for the oxidative C-C bond cleavage has been developed. The reaction proceeds in air using molecular oxygen as the oxidant, affording one-carbon shortened esters in moderate to good yields within a short time. Moreover, it provides a model reaction for the highly enantioselective synthesis of (d)-serine esters by combining with a l-proline catalyzed Mannich reaction.
- Hu, Bin,Li, Yunfeng,Li, Zhongjun,Meng, Xiangbao
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supporting information
p. 4138 - 4141
(2013/07/05)
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- Nitromethane with IBX/TBAF as a nitrosating agent: Synthesis of nitrosamines from secondary or tertiary amines under mild conditions
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Aliphatic or aromatic N,N-disubstituted nitrosamine was generated in fair to excellent yield from the reaction of a secondary or tertiary amine with o-iodoxybenzoic acid (IBX) or o-iodosylbenzoic acid (IBA)/R4NX (X = halide) and nitromethane. The product yield was strongly influenced by both the halide of R4NX and iodanes. IBX gave a higher yield than IBA, while the halides follow F- > Cl- > Br- ~ I-. Nitrous acid formed in situ from nitromethane and IBX (or IBA)/halides is likely responsible for the observed reaction.
- Potturi, Hima K.,Gurung, Ras K.,Hou, Yuqing
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experimental part
p. 626 - 631
(2012/02/16)
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- Oxidative cleavage and rearrangement of aryl epoxides using iodosylbenzene: On criegee's trail
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Aryl epoxides undergo rearrangement and oxidative cleavage when reacted with in situ prepared hydroxy-λ3-iodane complexes. The presence of H2O plays a decisive role in steering the reaction path. A mechanistic scheme is proposed that accounts for the observed chemoselectivities. Copyright
- Havare, Nizam,Plattner, Dietmar A.
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p. 2036 - 2042
(2013/01/15)
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- Oxidative cleavage of α-aryl aldehydes using iodosylbenzene
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We found that α-aryl aldehydes can be cleaved to chain-shortened carbonyl compounds and formaldehyde by various iodosylbenzene complexes. A mechanistic scheme is presented that accounts for the loss of one carbon atom. Formaldehyde is further oxidized to CO and CO2 under the reaction conditions.
- Havare, Nizam,Plattner, Dietmar A.
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supporting information
p. 5078 - 5081,4
(2020/09/15)
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- Facile preparation and reactivity of bifunctional ionic liquid-supported hypervalent iodine reagent: A convenient recyclable reagent for catalytic oxidation
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Novel, efficient, and recyclable bifunctional catalysts bearing ionic liquid supported (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and iodoarene moieties were developed and used for environmentally benign catalytic oxidation of alcohols. The reactions using peracetic acid as a green and practical co-oxidant afforded the corresponding carbonyl compounds in high yields under mild conditions and convenient work-up. Furthermore, these ionic liquid supported bifunctional catalysts could be simply recovered and reused.
- Zhu, Chenjie,Yoshimura, Akira,Wei, Yunyang,Nemykin, Victor N.,Zhdankin, Viktor V.
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supporting information; experimental part
p. 1438 - 1444
(2012/04/04)
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- Structure-Reactivity correlation in the oxidation of substituted benzaldehydes by tetraethylammonium chlorochromate
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Oxidation of 36 monosubstituted benzaldehydes by tetraethylammonium chlorochromate in dimethyl sulphoxide, leads to the formation of corresponding benzoic acids. The reaction is of first order with respect to chlorochromate and aldehydes. The reaction is promoted by H+; the H+ dependence has the form kobs = a + b[H+]. The oxidation of duteriated benzaldehyde exhibits substantial primary kinetic isotope effect. The reaction was studied in 19 different organic solvents and the effect of solvent was analyzed using Taft's and Swain's multiparametric equations. The rates of the oxidation of para- and meta-substituted benzaldehydes showed excellent correlation in terms of Charton's triparametric LDR equation, whereas the oxidation of ortho-substituted benzaldehydes were correlated well with tetraperametric LDRS equation. The oxidation of para-substituted benzaldehydes is more susceptible to the delocalized effect than is the oxidation of ortho- and meta- substituted compounds, which display a greater dependence on the field effect. The positive value of h suggests the presence of an electron-deficient reaction centre in the rate-determining step. The reaction is subjected to steric acceleration by the orthosubstituents. A suitable mechanism has been proposed.
- Gehlot,Prasadrao,Sharma
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experimental part
p. 1173 - 1178
(2012/01/05)
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- Novel hydrazone-based tripodal sensors: Single selective colorimetric chemosensor for acetate in aqueous solution
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A series of novel tripodal colorimetric anion sensors based on hydrazone CH=N - NH groups have been synthesized and their recognition behavior with anionic guests has been studied. In DMSO solutions, sensors 1 and 2 show colorimetric responses for F-
- Zhang, Youming,Li, Qiao,Zhang, Qinsheng,Lin, Qi,Cao, Cheng,Liu, Mingxia,Wei, Taibao
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experimental part
p. 1529 - 1534
(2011/11/07)
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- Studies on the kinetics of tetraethylammonium bromochromate oxidation of some meta- and para-substituted benzyl alcohols in non-aqueous media
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Tetraethylammonium bromochromate (TEABC) oxidation of 18 meta- and para-substituted benzyl alcohols (BnOH) in dimethylsulphoxide (DMSO) leads to the formation of corresponding aldehydes. The reaction is first order each in TEABC and the alcohols. The reaction is catalyzed by hydrogen ions. The hydrogen ion dependence has the form: kobs = a+b[H+]. The oxidation of αα′-dideuterio benzyl alcohol exhibited a substantial primary kinetic isotope effect (kH/kD = 5.71 at 303 K). Oxidation of benzyl alcohol was studied in 17 different organic solvents. The solvent effect has been analyzed using Kamlet's and Swain's multi parametric equation. A correlation of data with Kamlet-Taft solvatochromic parameters (α, β, π*) suggests that the specific solute-solvent interactions play a major role in governing the reactivity. A mechanism involving a hydride ion transfer via chromate ester is proposed. by Oldenbourg Wissenschaftsverlag, Mu?nchen.
- Mansoor, S. Sheik,Shafi, S. Syed
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experimental part
p. 249 - 263
(2011/04/17)
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- Facile preparation and reactivity of polystyrene-supported (dichloroiodo)benzene: A convenient recyclable reagent for chlorination and oxidation
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A facile one-pot preparation of polystyrene-supported (dichloroiodo)benzene (loading of -ICl2 up to 1.35 mmol/g) from polystyrene, iodine, and bleach has been developed. This recyclable reagent is useful for efficient chlorination of organic substrates and selective oxidation of various alcohols to the corresponding carbonyl compounds in high yields under mild conditions. The final products are conveniently separated from the polymeric byproduct by simple filtration and isolated in good purity after evaporation of solvent.
- Chen, Jiang-Min,Zeng, Xiao-Mei,Middleton, Kyle,Zhdankin, Viktor V.
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supporting information; experimental part
p. 1952 - 1955
(2011/04/25)
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- Preparation, X-ray structure, and reactivity of 2-iodylpyridines: Recyclable hypervalent iodine(V) reagents
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2-Iodylpyridine and four examples of 3-alkoxy-2-iodylpyridines were prepared by oxidation of the respective 2-iodopyridines with 3,3-dimethyldioxirane. Structures of 2-iodylpyridine, 2-iodyl-3- isopropoxypyridine, and 2-iodyl-3-propoxypyridine were established by single-crystal X-ray diffraction analysis. 2-Iodyl-3-propoxypyridine has moderate solubility in organic solvents (e.g., 1.1 mg/mL in acetonitrile) and can be used as a recyclable reagent for oxidation of sulfides and alcohols. The reduced form of this reagent, 2-iodo-3-propoxypyridine, can be effectively separated from the reaction mixture by treatment with diluted sulfuric acid and recovered from the acidic aqueous solution by adding aqueous sodium hydroxide.
- Yoshimura, Akira,Banek, Christopher T.,Yusubov, Mekhman S.,Nemykin, Victor N.,Zhdankin, Viktor V.
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experimental part
p. 3812 - 3819
(2011/07/08)
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- Synthesis, spectral and catalytic activity of some Manganese(II) bis-benzimidazole diamide complexes
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Four Mn(II) complexes bound to a neutral bis-benzimidazole diamide ligand N,N′-bis(2-methyl benzimidazolyl 2,2′-oxy-diethanamide) (GBOA) have been synthesized and characterized. Anionic ligand associated with the complexes varies as Cl- CH3COO-, SCN- and ClO4-. X-ray structure of one of the complexes [Mn(GBOA)2(H2O)2]Cl2·4H 2O was solved and shows that the Mn(II) ion is hexacoordinate. Two equatorial positions are occupied by benzimidazole imine nitrogen atoms while the other two sites are occupied by amide carbonyl oxygens. The imine nitrogen and carbonyl oxygens are bound to Mn(II) by different arms of the two ligands while axial sites are occupied by two water molecules. Two Cl- anions are outside the coordination sphere and form an extensive 3D H-bonded network. Axially distorted octahedral geometry is confirmed for all the four complexes by low temperature EPR spectroscopy. Distortion parameter D was found to be similar for [Mn(GBOA)2(H2O)2]Cl 2·4H2O and [Mn(GBOA)2(H 2O)2]·(CH3COO)2·H 2O. Cyclic voltammograms have been obtained for all the four complexes and E1/2 values are dependant on the anionic ligand being in the coordination sphere or outside. [Mn(GBOA)2(H 2O)2]Cl2·4H2O and [Mn(GBOA)2(H2O)2]·(CH 3COO)2·H2O carry out the selective oxidation of N-benzyldimethylamine, and 1-methyl-pyrollidine to their respective carbonyl products with catalytic efficiency of 35-50%.
- Mohapatra, Subash Chandra,Hundal,Mathur, Pavan
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experimental part
p. 1634 - 1641
(2011/10/03)
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- Synthesis, FT-IR and DTA studies of mercury complexes of hydrazones
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N-Benzylidene-N-(2,4-dinitrophenyl)hydrazine (L1) and dimetheyl-{4-[(4-nitro-2-nitrosophenyl)hydrazonomethyl]phenyl}amine (L 2) were used as ligands for the synthesis of mercury(II) complexes. Vibrational study in the solid state of
- Sahebalzamani, Hajar,Ghammamy, Shahriare,Mehrani, Kheyrollah,Salimi, Farshid,Tarighi, Nayier Mohammadian
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experimental part
p. 26 - 28
(2011/11/13)
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- Efficient solvent-free synthesis of thiazolidin-4-ones from phenylhydrazine and 2,4-dinitrophenylhydrazine
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An efficient solvent-free synthesis of thiazolidinones from reaction of mercaptoacetic acid, aldehydes (benzaldehyde and valeraldehyde) or ketones (cyclopentanone and cyclohexanone), and hydrazines (phenylhydrazine and 2,4-dinitrophenylhydrazine) is reported. The compounds were generally characterized by spectroscopic techniques and specifically for 2-cyclohexanyl-3-(N-phenyl)-1,3-thiazolidin-4-one by X-ray crystallography.
- Neuenfeldt, Patrícia D.,Drawanz, Bruna B.,Siqueira, Geonir M.,Gomes, Claudia R.B.,Wardell, Solange M.S.V.,Flores, Alex F.C.,Cunico, Wilson
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supporting information; experimental part
p. 3106 - 3108
(2010/07/18)
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- Biocidal and catalytic efficiency of ruthenium(III) complexes with tridentate Schiff base ligands
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The reaction of the Schiff bases (obtained by condensing isatin with o-aminophenol/o-aminothiophenol/o-aminobenzoic acid) with [RuX 3(EPh3)3] (where X = Cl/Br; E = P/As) in benzene afforded new, air-stable Ru(III) complexes of the general formula [Ru(L)X(EPh3)2] (L = dianion of tridentate Schiff bases). In all these reactions, the Schiff base ligand replaces one triphenylphosphine/ triphenylarsine and two chlorides/bromides from the ruthenium precursors. The complexes were characterized by elemental analyses, spectral (FT-IR, UV-vis,1H and 13C NMR for the ligands, and EPR) and electrochemical studies. All the metal complexes exhibit characteristic LMCT absorption bands in the visible region. The catalytic reactivity proved these complexes to be efficient catalysts in the oxidation of alcohols and C-C coupling. All the complexes were screened for their biocidal efficiency against bacteria such as Staphylococcus epidermidis and Escherichia coli and fungi such as Botrytis cinerea and Aspergillus niger at 0.25,0.50 and 1 % concentrations.
- Arunachalam,Priya, N. Padma,Boopathi,Jayabalakrishnan,Chinnusamy
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experimental part
p. 491 - 498
(2010/10/18)
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- Studies on the kinetics of tripropylammonium fluorochromate oxidation of some aromatic alcohols in non-aqueous media
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The oxidation of benzyl alcohol (BnOH) and a few para-substituted benzyl alcohols by tripropylammonium fluorochromate (TriPAFC) in dimethylsulphoxide (DMSO) leads to the formation of corresponding aldehydes. The reaction is first order each in TriPAFC and the alcohols. The reaction is catalysed by hydrogen ions. The hydrogen ion dependence has the form: kobs = a + b[H +]. The oxidation of α α′-dideuterio benzyl alcohol exhibited a substantial primary kinetic isotope effect (kH/k D = 5.45 at 303 K). Oxidation of benzyl alcohol was studied in 19 different organic solvents. The solvent effect has been analysed using Kamlet's and Swain's multiparametric equation. A mechanism involving a hydride ion transfer via chromate ester is proposed.
- Mansoor, S. Sheik,Shafi, S. Syed
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experimental part
p. 85 - 90
(2011/10/18)
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- Synthesis, characterization, redox, catalytic, and antibacterial activities of binuclear ruthenium(III) schiff base complexes containing triphenylphosphine as co-ligand
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New hexa-coordinated binuclear Ru(III) Schiff base complexes of the type [(PPh3)2X2Ru]2L (where, X = Cl or Br; L = binucleating N2O2 Schiff bases) have been synthesized and characterized by elemental analysis, magnetic susceptibility measurement, FT-IR, UV-vis, 13C1H-NMR, ESR, cyclic voltammetric, SEM and powder X-ray diffraction pattern. The new complexes have been used as catalyst in C C coupling reaction and the oxidation of alcohols to their corresponding carbonyl compounds by using molecular oxygen atmosphere at ambient temperature. Further, the new Schiff base ligands and their Ru(III) complexes were also screened for their antibacterial activity against K. pneumoniae, Shigella sp., M. luteus, E. coli and S. typhi. From this study, it was found out that the activity of the ruthenium(III) Schiff base complexes almost reaches the effectiveness of the conventional bacteriocide standards. Copyright Taylor & Francis Group, LLC.
- Manimaran, Arumugam,Jayabalakrishnan, Chinnasamy
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experimental part
p. 116 - 128
(2010/08/13)
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- Effect of the micellar surfactant nanoreactors on the reactions of 2,4-dinitrophenylhydrazine with some aldehydes
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By thermogravimetry, the IR and electronic spectroscopy physicochemical characteristics of systems including aromatic aldehydes, 2,4- dinitrophenylhydrazine, and a surfactant were investigated. Selective solubilization effect of the cationic surfactant (c
- Doronin,Chernova,Burmistrova
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p. 903 - 907
(2008/12/20)
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- Correlation analysis of reactivity in the oxidation of substituted benzyl alcohols by 2,2′-bipyridinium chlorochromate
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Oxidation of benzyl alcohol and some ortho-, meta- and para-monosubstituted ones by 2.2′-bipyridinium chlorochromate (BPCC) in DMSO leads to the formation of corresponding benzaldehydes. The reaction is first order in both BPCC and the alcohol. The reaction is promoted by hydrogen ions; the hydrogen-ion dependence has the form : kobs = a + b [H+]. Oxidation of α,α-dideuteriobenzyl alcohol (PhCD2OH) has exhibited a substantial primary kinetic isotope effect (kH/k D = 5.60 at 298 K). The reaction has been studied in nineteen organic solvents and the effect of solvent analysed using Taft's and Swain's multi-parametric equations. The rates of oxidation of para- and meta-substituted benzyl alcohols have been correlated in terms of Charton's triparametric LDR equation whereas the oxidation of ortho-substituted benzyl alcohols with tetraparametric LDRS equation. The oxidation of para-substituted benzyl alcohols is more susceptible to the delocalization effect than that of ortho- and meta-substituted compounds, which display a greater dependence on the field effect. The positive value of η suggests the presence of an electron-deficient reaction centre in the rate-determining step. The reaction is subjected to steric acceleration by the ortho-substituents. A suitable mechanism has been proposed.
- Yajurvedi, Deeksha,Baghmar, Manju,Sharma, Pradeep K.
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experimental part
p. 496 - 501
(2009/07/18)
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- Structure-reactivity correlation in the oxidation of substituted benzaldehydes by 2,2-bipyridinium chlorochromate
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Oxidation of thirty six monosubstituted benzaldchydes by 2,2′-bipyridiniuin chlorochromate (BPCC) in diniethylsulphoxide (DMSO), leads to the formation of corresponding benzoic acids. The reaction is of first order with respect to both BPCC and aldehydes. The reaction is promoted by hydrogen ions; the hydrogen ion dependence has the form kobs= a + b[H+]. The oxidation of [2H]benzaldehyde (PhCDO) exhibited a substantial primary kinetic isotope effect. The reaction was studied in nineteen different organic solvents and the effect of solvent was analysed using Taft's and Swain's multi-parametric equations. The rates of the oxidation of para- and mete-substituted benzaldehydes showed excellent correlation in terms of Charton's triparametric LDR equation, whereas the oxidation of orfAo-substituted benzaldehydes were correlated well with tetraparametric LDRS equation. The oxidation of para-substituted benzaldehydes is more susceptible to the delocalized effect than is the oxidation of ortho- and mem-substituted compounds, which display a greater dependence on the field effect. The positive value of η suggests the presence of an electron-deficient reaction centre in the rate-determining step. The reaction is subjected to steric acceleration by the ortho-substituents. A suitable mechanism has been proposed.
- Sharma, Pradeep K.
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experimental part
p. 1281 - 1288
(2009/12/31)
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- m-iodosylbenzoic acid as a convenient recyclable reagent for highly efficient RuCl3-catalyzed oxidation of alcohols to carbonyl compounds
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m-Iodosylbenzoic acid selectively oxidizes primary and secondary alcohols to the respective carbonyl compounds in the presence of RuCl3 (0.5 mol%) at room temperature in aqueous acetonitrile. Separation of pure products is conveniently achieved by scavenging any aryl iodide by ion exchange with IRA-900 (hydroxide form) or by simple extraction of the basic aqueous solution with water. The reduced form of the reagent, m-iodobenzoic acid, can be easily recovered from the ion-exchange resin or from the basic aqueous solution by simple acidification with HCl. Georg Thieme Verlag Stuttgart.
- Yusubov, Mekhman S.,Gilmkhanova, Marina P.,Zhdankin, Viktor V.,Kirschning, Andreas
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p. 563 - 566
(2007/10/03)
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- An efficient tandem oxidative-protection reaction of benzylic alcohols to corresponding arylhydrazones and oximes
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A mild and efficient one-pot synthesis of hydrazones and oximes from the reaction of the oxidation product of benzyl alcohols and phenols by 3,6-bis(triphenylphosphonium)cyclohexene dichromate with phenylhydrazine, 2,4-dinitrophenylhydrazine, and hydroxylamine is described. Copyright Taylor & Francis Group, LLC.
- Badri, Rashid,Shushizadeh, Mohammad Reza
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p. 601 - 605
(2007/10/03)
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- Spectral regression and correlation coefficients of some benzaldimines and salicylaldimines in different solvents
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Sixteen Schiff bases obtained from the condensation of benzaldehyde or salicylaldehyde with various amines (aniline, 4-carboxyaniline, phenylhydrazine, 2,4-dinitrophenylhydrazine, ethylenediamine, hydrazine, o-phenylenediamine and 2,6-pyridinediamine) are
- Hammud, Hassan H.,Ghannoum, Amer,Masoud, Mamdouh S.
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p. 255 - 265
(2007/10/03)
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- Ferric(III) nitrate supported on kieselguhr: A new reagent for selective oxidation of alcohols
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A selective and effective oxidation of alcohols into the corresponding aldehydes and ketones, respectively, with a new reagent, ferric(III) nitrate supported on kieselguhr, under heterogeneous conditions is reported. Copyright Taylor & Francis Group, LLC.
- Lou, Ji-Dong,Zhu, Long-Hua,Ma, Yi-Chun,Li, Li
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p. 3061 - 3064
(2007/10/03)
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- Methods for producing D-beta-hydroxyamino acids
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An objective of the present invention is to provide efficient methods for producing D-β-hydroxyamino acids (formula 2 or 4), such as D-erythro-2-amino-3-cyclohexyl-3-hydroxypropionic acid, which are useful as intermediates in the synthesis of pharmaceutical products and others. The present invention makes it possible to efficiently produce D-erythro-2-amino-3-cyclohexyl-3-hydroxypropionic acid by cleaving unnecessary L-erythro-2-amino-3-cyclohexyl-3-hydroxypropionic acid in industrially feasible concentrations of DL-erythro-2-amino-3-cyclohexyl-3-hydroxypropionic acid used as starting material by using Pseudomonas putida-derived L-phenylserine aldolase.
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Page/Page column 5-6
(2008/06/13)
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- Novel synthesis, properties, and NAD+-NADH type redox ability of 1,3-dimethylcyclohepta[4,5]pyrrolo[2,3-d]pyrimidine-2,4(1,3H)-dionylium ions annulated with additional pyrrolo[2,3-d]pyrimidine-1,3(2,4H)-dione and furan analogue, and their hydride adducts
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A convenient preparation of novel cations 11a,b+·BF 4- and 12a,b+·BF4 -, which are derived from annulation of the 1,3-dimethylcyclohepta[4, 5]pyrrolo[2,3-d]pyrimidine-2,4(1,3H)-dionylium ion with additional pyrrolo[2,3-d]pyrimidine-1,3(2,4ii)-dione and a furan analogue, was accomplished by a novel oxidative cyclization of 1,7-dihydro-7-[1′,3′-dimethyl- 2′,4′(1′,3′H)-dioxo-6′-(phenylamino) -pyrimidin-5′-yl]-1,3-dimethyl-10-phenylcyclohepta[4,5]pyrrolo[2,3-d] pyrimidine-2,4(1,3H)-dione 9 and its furan-analogue by using DDQ or photoirradiation under aerobic conditions. Structural characteristics of 11a,b+ and 12a,b+ were clarified on inspection of the UV-vis and NMR spectral data as well as X-ray crystal analyses. The stability of cations 11a,b+ and 12a,b+ is expressed by the pK R+ values that were determined spectrophotometrically to be 10.7-12.6. The electrochemical reduction of 11a,b+·BF 4 and 12a,b+·BF4- exhibited reduction potential at -0.93 to -1.00 (V vs Ag/AgNO3). The first reduction potential of 11a+ was reversible due to steric hindrance of two phenyl groups. The photoinduced oxidation reaction of 11a,b +·BF4- and 12a,b+· BF4- toward some amines under aerobic conditions was carried out to give the corresponding imines (isolated by converting to the corresponding 2,4-dinitrophenylhydrazones) with the recycling numbers of 0.6-30.3. Furthermore, as an example of the NAD+-NADH models, the reduction of a pyruvate analogue and some carbonyl compounds with the hydride-adduct of 11a+-BF4- was accomplished for the first time to give the corresponding alcohol derivatives.
- Naya, Shin-Ichi,Nishimura, Junya,Nitta, Makoto
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p. 9780 - 9788
(2007/10/03)
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- Dowex polymer-mediated protection of carbonyl groups
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Dowex (strongly acidic cationic exchange resin) polymer is employed as solid acid catalyst for the clean and less hazardous protection of carbonyl compounds as phenylhydrazones and 2,4-dintrophenylhydrazones in ethanol under reflux conditions. The reactions proceed very smoothly and the yields of the derivatives are excellent. Copyright Taylor & Francis, Inc.
- Niknam, Khodabakhsh,Kiasat, Ali Reza,Karimi, Sadegh
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p. 2231 - 2236
(2007/10/03)
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- In situ alcohol oxidation-protection reactions
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The one-pot conversion of primary and secondary alcohols into phenylhydrazones and 2,4-dintrophenylhydrazones is reported using chromium trioxide supported on silica gel and phenylhydrazines or 2,4- dintrophenylhydrazines under solvent-free conditions. This oxidation arylhydrazone formation reaction has been applied to a range of aliphatic and benzylic alcohols. Copyright Taylor & Francis, Inc.
- Kiasat,Kazemi,Nourbakhsh
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p. 1555 - 1558
(2007/10/03)
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