- Thiol-yne click reaction: an interesting way to derive thiol-provided catechols
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The hydrothiolation of activated alkynes is presented as an attractive and powerful way to functionalize thiols bearing catechols. The reaction was promoted by a heterogeneous catalyst composed of copper nanoparticles supported on TiO2 (CuNPs/TiO2) in 1,2-dichloroethane (1,2-DCE) under heating at 80 °C. The catalyst could be recovered and reused in three consecutive cycles, showing a slight decrease in its catalytic activity. Thiol derivatives bearing catechol moieties, obtained through a versatile Michael addition, were reacted with different activated alkynes, such as methyl propiolate, propiolic acid, propiolamide or 2-ethynylpyridine. The reaction was shown to be regio- and stereoselective towards anti-Markovnikov Z-vinyl sulfide in most cases studied. Finally, some catechol derivatives obtained were tested as ligands in the preparation of coordination polymer nanoparticles (CNPs), by taking the advantage of their different coordination sites with metals such as iron and cobalt.
- Nador, Fabiana,Mancebo-Aracil, Juan,Zanotto, Duham,Ruiz-Molina, Daniel,Radivoy, Gabriel
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p. 2074 - 2082
(2021/01/29)
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- Synthesis of dimethyl acetylenedicarboxylate
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The invention discloses synthesis of dimethyl acetylenedicarboxylate. The synthesis steps comprise: (1) dissolving 2,3-dibromosuccinic acid in methanol, adding concentrated sulfuric acid to the reaction solution in a dropwise manner, continuously stirring, and carrying out a reaction for 2-3 h to obtain 2,3-methyl dibromosuccinate; and (2) dissolving the 2,3-methyl dibromosuccinate obtained in thestep (1) into ethanol, adding an alkali substance, stirring, carrying out a heating reflux reaction, and carrying out post-treatment to obtain dimethyl acetylenedicarboxylate. According to the present invention, the operation is simple, the requirement on the operation technology of the technician is not high, the production cost can be effectively saved, and the dimethyl acetylenedicarboxylate obtained through the method has the high purity and can be directly used for the next reaction.
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Paragraph 0013-0014; 0016; 0020; 0024
(2018/10/11)
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- A 2- fluoro fumaric acid ester (formula I) and its preparation method and application
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The invention discloses 2-fuloro fumarate (formula I) and a preparation method thereof. Experiments show that: the kinds of compounds are capable of effectively inhibiting NF-kB transcriptional activity introduced by TNF-alpha, and further are capable of treating diseases introduced by NF-kB, such as psoriasis, multiple sclerosis, arthritis, eye inflammation or allergy, asthma and lupus erythematosus, and can be used as an immunosuppressant for organ transplantation.
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Paragraph 0059
(2017/01/23)
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- Mechanism and scope of the base-induced dehalogenation of (E)-diiodoalkenes
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A wide range of nucleophiles have induced the elimination of iodine from (E)-diiodoalkenes to form alkynes under surprisingly mild conditions. The iodide anion is particularly efficient, and can drive the reaction to completion in less than 1 hour at room temperature in a polar aprotic solvent. Detailed investigations have suggested the reaction has a bimolecular polar mechanism. The deiodination reaction can be driven to completion with 1 equiv. of nucleophile and is partially catalytic with substoichiometric amounts of deiodinating reagent. Kinetic analysis of the stoichiometric iodide-induced reaction indicated an overall pseudo-first-order behavior. The reaction exhibited strong solvent effects, with much slower reactions observed in protic solvents than in polar aprotic solvents. The substrate dimethyl (2E)-2,3-diiodo-butene-2-dioate demonstrated orthogonal reactivity for either elimination or hydrolysis, depending on the solvent and nucleophile used. This reaction is a major pathway for all the diiodoalkenes examined, and represents a challenge and an opportunity for using these substrates in organic synthesis.
- Resch, Daniel,Lee, Chang Heon,Tan, Siew Yoong,Luo, Liang,Goroff, Nancy S.
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p. 730 - 737
(2015/01/30)
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- PREPARATION OF ORGANOSILICON-CONTAINING TRIAZOLES
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The disclosure includes methods for preparing organosilicon-containing 1,2,3-triazoles by reacting an organosilicon containing azide with an alkyne compound or an organosilicon containing alkyne with an azide compound under thermal reaction conditions.
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- Synthesis and transformations of 5-substituted 2-aryl-7H-[1,2,4]triazolo[3, 2-b][1,3]thiazin-7-ones and 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a] benzimidazol-4-ones
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3-Aryl-1,2,4-triazole-5-thiones react with dimethyl acetylenedicarboxylate and methyl 3-phenyl-propynoate to afford the corresponding 5-substituted 2-aryl-7H-[1,2,4]triazolo[3,2-b][1,3]thiazin-7-ones. Treatment of 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones with alkalies leads to formation of 3-(benzimidazol-2-ylsulfanyl)-3-arylpropionic acids, their reaction with methyl p-toluenesulfonate yields 1-(3-methyl-2-thioxo-2,3- dihydro-1N-benzimidazol-1-yl)-3-phenyl-2-propen-1-one, and oxidation with hydrogen peroxide gives benzimidazole-2-sulfonic acid and 3-aryl-2-propenoic acids. 2005 Pleiades Publishing, Inc.
- Britsun,Esipenko,Chernega,Lozinskii
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p. 108 - 113
(2007/10/03)
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- 7-oxabicyclo[2.2.1]heptadiene derivatives: Reactivity towards Bronsted acids
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7-Oxabicyclo[2.2.1]heptadiene derivatives can be converted to phenols, fulvenes and/or the products from a retro-Diels-Alder-like reaction by treatment with Bronsted acids; the outcome of the reaction depends on the experimental conditions and the nature of the Bronsted acid used.
- Maggiani, Alain,Tubul, Arlette,Brun, Pierre
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p. 2495 - 2496
(2007/10/03)
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- Reductive dehalogenation of aliphatic vic-dihalides with metallic samarium in a methanolic medium
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In the title reaction, eight vic-dibromides and three vinylene dibromides gave the corresponding debromination products (alkenes and alkynes) at room temperature under neutral condition and an argon atmosphere. 2,3-Dibromosuccinic acid derivatives gave overreduction products or an unusual coupling dimer.
- Yanada, Reiko,Negoro, Nobuyuki,Yanada, Kazuo,Fujita, Tetsuro
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p. 9313 - 9316
(2007/10/03)
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- Barrelene Derivatives-Potential Modules for Assembly
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Dihydrobarrelene tetraamide 8 was prepared by Diels-Alder reaction of 4 and 5 and indirect transformation of the ester into amide groups.The crystal structure of 8 showed an unpredicted conformation of the four amide groups.
- Beerly, Rene,Rebek, Julius
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p. 1813 - 1816
(2007/10/02)
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- Synthesis of acetylenedicarboxylic acid esters and asymmetric Diels-Alder reactions of the bis(methyl (S)-lactyl) ester
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A general method has been developed for the preparation of acetylenedicarboxylic acid esters and applied to the synthesis of both achiral and chiral esters.Diels-Alder reactions of one of the chiral esters, the bis(methyl (S)-lactyl) ester, with various types of dienes, such as phenylbutadiene, orthoquinodimethanes, and isobenzofuran, have been investigated.Moderate asymmetric induction was observed in reactions with dienes bearing an α-hydroxyl group.In one case, an unusual solvent-induced reversal of asymmetric induction was observed.Key words: acetylenedicarboxylic acid esters, phenylbutadiene, orthoquinodimethanes, isobenzofurans, Diels-Alder , asymmetric.
- Charlton, James L.,Chee, Gaiklean,McColeman, Heather
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p. 1454 - 1462
(2007/10/03)
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- Synthesis of Chiral Esters of Acetylenedicarboxylic Acid
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A general method for the preparation of acetylenedicarboxylic acid esters has been investigated and several esters have been prepared in excellent yield.The bis-(methyl (S)-lactyl), bis-(methyl (R)-mandelyl), and bis-menthyl esters were prepared, as well as achiral diaryl and dialkyl esters.The esters were synthesized from the corresponding dibromofumarates by 2,3-dibromo elimination using zinc or zinc amalgam in THF at room temperature or at reflux.The dibromofumarates were prepared by the esterification of dibromofumaryl chloride with the corresponding alcohols.
- Charlton, James L.,Chee, Gaiklean
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p. 6243 - 6246
(2007/10/02)
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- Flash Vacuum Pyrolysis of Stabilized Phosphorous Ylides. Part 5. Selective Extrusion of Ph3PO from β,γ,β'-Trioxo Ylides to give Doacylalkynes
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Sixteen examples of the previously unknown trioxo ylides 7 have been prepared by acylation of stabilized phosphorus ylides 8 with α-oxo acid chlorides 9.Extrusion of Ph3PO from these is readily achieved using FVP at 500 deg C in most cases, to afford the diacylalkynes 10 in moderate yield.Three examples failed to give the expected alkynes and the nature of the processes involved in these cases is certain.Fully assigned 13C NMR spectra are presented for the ylides and an unexpected pattern is observed in the value of JP-C for the three carbonyl carbons depending on the nature of the substituents present.There is some correlation between the value of 2JP-C for the central carbonyl carbon and the success of the pyrolysis although this is not complete.The method has been used to prepare a specifically 13C labelled acetylenic diester 14.
- Aitken, R. Alan,Herion, Hugues,Janosi, Amaya,Karodia, Nazira,Raut, Swati V.,et al.
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p. 2467 - 2472
(2007/10/02)
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- Pyrolysis of β,γ,β'-trioxo phosphorus ylides: Convenient synthesis of symmetrical and unsymmetrical diacylalkynes
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Flash vacuum pyrolysis of a series of 1,2,4-trioxo-3-triphenylphosphoranylidene-butane derivatives, formed by acylation of β-oxo-phosphorus ylides with α-oxo-acid chlorides, results in extrusion of Ph3PO exclusively across the 2,3-position to give diacylalkynes.
- Aitken,Herion,Janosi,Raut,Seth,Shannon,Smith
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p. 5621 - 5622
(2007/10/02)
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- The hurtley reaction. 2. Novel complexes of disubstituted acetylenes with copper(I) benzoates having a reactive ortho C-Cl or C-Br bond. X-ray structural characterization of tetrakis(2-chlorobenzoato)bis(diethyl acetylenedicarboxylate)tetracopper(I)
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Tetrameric copper(I) benzoate, [Cu(μ-O2CC6H5)]4 (1a), and the o-halogen-substituted copper(I) benzoates [Cu(μ-O2CC6H4-2-Cl)]4 (1b) and [Cu(μ-O2CC6H4-2-Br)]4 (1c), the postulated intermediates in the Hurtley reaction, react with the activated disubstituted acetylenes dimethyl acetylenedicarboxylate (DMAD) and diethyl acetylenedicarboxylate (DEAD) in diethyl ether to yield the stable, soluble, tetranuclear complexes [Cu4(μ-O2CC6H4-2-X) 4(μ-DMAD)2] (X = H (2a), Cl (2b), Br (2c)) and [Cu4(μ-O2CC6H4-2-X) 4(μ-DEAD)2] (X = H (3a), Cl (3b), Br (3c)). The reaction of 1b and 1c with diphenylacetylene in diethyl ether yields the dinuclear complexes [Cu(μ-O2CC6H4-2-X)(PhC≡CPh)] 2 (X = Cl (4b), Br (4c)). In methanol the reaction of [Cu(μ-O2CC6H5)]4 (1a) with DMAD shows a different reactivity pattern, leading to the trimerization of the alkyne. An X-ray structure determination of 3b (C44H36Cl4Cu4O16, triclinic, space group P1, a = 10.973 (3) A?, b = 20.926 (4) A?, c = 10.949 (4) A?, α = 96.76 (2)°, β = 90.96 (3)°, γ = 104.55 (3)°, and Z = 2) has been carried out. The structure, refined to a final R factor of 0.053 with use of 7016 reflections, shows it to be the first copper(I) benzoate compound wherein four copper(I) atoms form a distorted-tetrahedral core. Each of the four benzoate units, acting as a four-electron donor, bridges two adjacent copper atoms (Cu?Cu = 3.027 A? (av)). The two remaining edges of the tetrahedral copper(I) core (Cu?Cu = 2.950 A? (av)) are each perpendicularly bridged by an acetylene unit acting as a four-electron donor; this is the first example of this bonding mode of unsaturated organic compounds in Cu(I) benzoates. All copper atoms have an almost trigonal surrounding consisting of two oxygen atoms (of different benzoates) and the midpoint of the acetylene triple bond. Our attempts to elucidate the structure of the analogous bromo compound 2c were only partially successful due to strong pseudosymmetry in the crystals. The overall structure of 2c appeared to be similar to that of 2b: complex 2c, C40H28Br4Cu4O16, space group Pa, P2/a, or P21/a (monoclinic) with a = 24.658 (4) A?, b = 16.838 (3) A?, c = 12.353 (3) A?, β = 90.08 (3)°, and Z = 4. Variable-temperature 1H NMR spectroscopy and molecular weight determinations of complexes 2 indicate partial dissociation of the coordinated acetylene ligands in solution.
- Aalten, Henk L.,Van Koten, Gerard,Riethorst, Ed,Stam, Casper H.
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p. 4140 - 4146
(2008/10/08)
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- Hypervalent Iodine Oxidation of 5-Substituted and 4,5-Disubstituted Pyrazol-3(2H)-ones: A Facile Synthesis of Methyl-2-alkynoates and Methyl 2,3-alkadienoates
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Hypervalent iodine oxidation of various 5-substituted pyrazol-3(2H)-ones (1a-h) with iodobenzene diacetate or iodosobenzene in methanol results in fragmentative loss of molecular dinitrogen to yield methyl 2-alkynoates (2a-h).However, 5-methyl-4-substituted pyrazol-3(2H)-ones (3a-d) under similar conditions yield methyl 2,3-allenic esters (4a-d).Methyl 2,3-cycloalkadienoates (6a-e) are obtained by the oxidative cleavage of 4,5-polymethylene pyrazol-3(2H)-ones (5c-e) using iodobenzene diacetate or iodosobenzene in methanol. 5-Methyl-4,4-disubstituted pyrazol-3(2H)-ones (7a-b) were found not to undergo raction under similar conditions.The scope and mechanism of these reactions are discussed.
- Moriarty, R. M.,Vaid, R. K.,Ravikumar, V. T.,Hopkins, T. E.,Farid, P.
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p. 1605 - 1610
(2007/10/02)
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- The chemistry of (fulvalene)dimolybdenum hexacarbonyl: A rigidly held dinuclear transition-metal complex
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The X-ray structure of (fulvalene)dimolybdenum hexacarbonyl [FvMo2(CO)6] has been determined. Thermal, photolytic, and chemical treatment failed to yield the metal-metal triply bonded complex FvMo2(CO)4, either because it was not formed or because of its instability; this result may have been caused by excessive bond strain in the fulvalene ligand. Photolysis of FvMo2(CO)6 in the presence of alkynes afforded mono- and bis(alkyne) complexes FvMo2(CO)4(RC≡CR) and FvMo2(CO)3(RC≡CR)2. Spectroscopic evidence indicated that the former bears as a ligand a μ-η2-alkyne and that this ligand partially moved about the Mo-Mo bond in a rapid fluxional process: ΔG≠ = 15 ± 0.5 kcal mol-1. The bis(alkyne) systems contained uncoupled alkynes as determined by an X-ray diffraction study of one complex. This result is unusual in light of the frequent occurrence of alkyne coupling at a dinuclear center. Reduction of FvMo2(CO)6 with Na-Hg or LiBEt3H furnished the dianion FvMo2(CO)62-. The latter reacted with protic acids and haloalkanes to give the respective dihydride FvMo2(CO)6H2 and dialkyl complexes FvMo2(CO)6R2 (R = CH3, CH2Ph, CH2OCH3). At 20°C the dihydride eliminated H2 with formation of FvMo2(CO)6. Treatment of FvMo2(CO)6(CH2OCH3)2 with HBF4·(Et2O) at -20°C (CD2Cl2) produced FvMo2(CO)6(CH2OCH3)(=CH 2)+, as determined by 1H NMR spectroscopy. Warming to 0°C gave the carbene-coupling product FvMo2(CO)6(C2H4)2+. The bis(carbene) FvMo2(CO)6(=CH2)22+ was not detected. The dianion FvMo2(CO)62- reacted with I(CH2)3I to give a metal-metal bonded 1-oxacyclopent-2-ylidene complex. An X-ray diffraction analysis showed that the Fischer-type carbene ligand was terminally bound. This complex exhibited fluxional behavior which may involve a bridging carbene species (ΔG≠ = 18 ± 0.5 kcal mol-1). Thermolysis (100°C) led to efficient generation of propene and FvMo2(CO)6 by a novel pathway.
- Drage, James S.,Vollhardt, K. Peter C.
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p. 280 - 297
(2008/10/08)
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- Novel reactions of metal-metal bonds. Reactions of Pd2{(C6H5)2PCH2P(C 6H5)2}2Cl2 with acetylenes, olefins, and isothiocyanates
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Acetylenes with electron-withdrawing substituents react with Pd2(dpm)2X2 (dpm = (C6H5)2PCH2P(C6H 5)2; X = Cl, Br, I) to form Pd2(dpm)2(μ-acetylene)X2 (acetylene = C2(CF3)2, C2(CO2CH3)2, C2(CO2C2H5)2, HC2CO2H, HC2CO2CH3) which have been characterized by infrared and 31P{1H} and 1H NMR spectroscopy. These acetylene adducts are resistant to acetylene exchange and to protonation. Reaction with methyl isocyanide yields [Pd2(dpm)2(μ-C2{CO2CH 3}2)-(CNCH3)2][[PF6] 2 which is also formed by reaction of [Pd2(dpm)2(μ-CNCH3)(CNCH3) 2][PF6]2 with dimethyl acetylenedicarboxylate. Pd2(dpm)2Cl2 is a catalyst for the cyclotrimerization of dimethyl acetylenedicarboxylate and Pd2-(dpm)2(μ-C2{CO2CH 3}2)Cl2 is formed during the reaction. The reaction of Pd2(dpm)2I2 with maleic anhydride results in the formation of Pd(dpm)I2 and two other incompletely characterized products which can also be obtained through the addition of maleic anhydride to Pd2(dpm)3. Ethylene, norbornadiene, and chlorotrifluoroethene are unreactive toward Pd2(dpm)2Cl2. Phenyl and methyl isothiocyanate react with Pd2(dpm)2Cl2 to yield Pd2(dpm)2(μ-CNR)Cl2 in 50% isolated yield; some Pd2(dpm)2(μ-S)Cl2 is formed in the process.
- Lee, Chung-L.I.,Hunt, Catherine T.,Balch, Alan L.
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p. 2498 - 2504
(2008/10/08)
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- Pharmaceutical compositions and methods of using thiadiazolo pyrimidinone compounds
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Substituted 7H-thiazolo- and 7H-thiadiazolo-pyrimidine-7-ones compounds and the drug composition containing same. The compounds are immunostimulants for mammals. A process of making these compounds and of using the drug composition.
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- 3-Aryl-4-isoxazolecarboxylic acids as plant growth regulants
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3-Aryl-4-isothiazolecarboxylic acids as well as 3-aryl-4-isoxazolecarboxylic acids have been found to be effective plant growth regulants especially when applied to soybean plants.
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