- MECHANISTIC INVESTIGATIONS WITH POSITIVE HALOGENS: KINETICS OF OXIDATION OF THIOSEMICARBAZIDE BY CHLORAMINE-B, BROMAMINE-B AND DICHLORAMINE-B IN ACID MEDIUM
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Kinetics of oxidation of thiosemicarbazide (TSC) by chloramine-B (CAB), and bromamine-B (BAB) in aqueous perchloric acid medium and by dichloramine-B (DCB) in 1:1 (v/v) water-methanol medium has been studied.The rate followed first order kinetics in and inverse fractional order in with all the oxidants.But it was fractional order in with CAB and independent of with BAB and DCB.Addition of benzenesulphonamide, the reduced product of the oxidants had no effect on the rate with CAB and BAB but it slightly increased the rate with DCB.Therate decreased with increase in ionis strength of the medium in all cases.Decrease of dielectric constant of the reaction medium by adding methanol had no effect on the rate with CAB and BAB but increased the rate with DCB.The mechanisms proposed and the derived rate laws are in conformity eith the observed results.The coefficients of the rate limiting steps have been calculated.Kinetics observed with HOCl and HOBr support the proposed mechanisms.
- Gowda, B. Thimme,Bhat, J. Ishwara
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- Osmium(VIII)-catalyzed kinetics and mechanism of indigo carmine oxidation by chloramine-B in basic medium
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Indigo carmine (IC) or sodium indigotin disulfonate is a natural dye that finds applications in clinical diagnosis, chemistry and biology. The osmium(VIII)-catalyzed oxidation of IC by chloramine-B (CAB) in alkaline solutions has been spectrophotometrically monitored at the indigo carmine λmax of 610 nm at 298 K. The reaction stoichiometry has been found to be 1:4 (mol:mol), resulting in the formation of major products that are the sodium salt of sulfonated anthranilic acid (SAA) and benzenesulfonamide (BSA). The reaction shows a first-order dependence of the rate on [IC], a fractional-order dependence each on [Os(VIII)] and [OH-], and a zero-order dependence each on [CAB], [BSA], and [SAA]. The variation of the ionic strength of the reaction medium has a negligible effect on the rate. Based on the effect of temperature in the range 288-313 K, activation parameters are evaluated from Arrhenius and Eyring plots. A mechanism consistent with the observed kinetic and activation data has been proposed and a rate law has been derived. Copyright Taylor & Francis Group, LLC.
- Cholkar, Kishore,Kouassi, Gilles K.,Ananda,Veeraiah,Gowda, Netkal M. Made
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- Synthesis and X-Ray Structure of Bistetraphenylphosphonium Tris(phenylsulphonylimino)sulphite
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An aza-analogue of sulphite, the structure of which was determined by X-ray diffraction, is prepared from sodium amide and a sulphur di-imide in liquid ammonia.
- Roesky, Herbert W.,Schmieder, W.,Sheldrick, William S.
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- Chloraminometric and bromaminometric oxidation of sulfanilic acid in alkaline medium: A comparative kinetic and mechanistic study
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The kinetics of oxidation of sulfanilic acid (SAA) by chloramine-B (CAB) and bromamine-B (BAB) has been investigated in alkaline medium at 35 ± 0.1°C. The oxidation reaction follows identical kinetics in the case of both the oxidants with first-order dependence on each [oxidant]o and [SAA]o and an inverse first-order dependence on [OH-]. The variation of ionic strength, dielectric constant of the medium, addition of the reaction product (benzene-sulfonamide), and halide ions showed no significant influence on the reaction rate. Proton inventory studies made in H2O-D2O mixtures for CAB and BAB have been utilized to calculate the isotopic fractionation factor. The reaction has been studied at different temperatures, and activation parameters for the composite reaction have been computed from the Arrhenius plots. N-Hydroxylaminobenzene-4-sulfonic acid was identified as the oxidation product of SAA from IR and GC-MS analysis. A mechanism consistent with the kinetic results is proposed in which PhSO 2NHX (X = Cl or Br) interact with the substrate in the rate-limiting step. A suitable rate law is derived. The rate of oxidation of sulfanilic acid is about fourfold faster in BAB compared to CAB. The oxidation of SAA brought about by CAT and BAT was also investigated under identical experimental conditions, and the overall rate of oxidation of SAA increases in the order: BAB > BAT > CAB > CAT This may be attributed to the difference in electrophilicities of Cl+ and Br+ ions and also the van der Waal's radii of chlorine and bromine.
- Puttaswamy,Jagadeesh
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- SELECTIVE NON-CYCLIC NUCLEOTIDE ACTIVATORS FOR THE CAMP SENSOR EPAC1
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The invention relates generally to novel EPAC1 activators, such as Formula (I) and (II) and the preparation thereof as well as the use of EPAC1 activators disclosed herein as to selectively activate EPAC1 in cells.
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Paragraph 00174-00176; 00198; 00277
(2021/09/26)
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- Synthesis, biological evaluation, and docking studies of novel pyrrolo[2,3-b]pyridine derivatives as both ectonucleotide pyrophosphatase/phosphodiesterase inhibitors and antiproliferative agents
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Ecto-nucleotide pyrophosphatases/phosphodiesterases (NPPs) together with nucleoside triphosphate diphosphohydrolases (NTPDases) and alkaline phosphatases (APs) are nucleotidases located at the surface of the cells. NPP1 and NPP3 are important members of NPP family that are known as druggable targets for a number of disorders such as impaired calcification, type 2 diabetes, and cancer. Sulfonylurea derivatives have been reported as antidiabetic and anticancer agents, therefore, we synthesized and investigated series of sulfonylurea derivatives 1a-m possessing pyrrolo[2,3-b]pyridine core as inhibitors of NPP1 and NPP3 isozymes that are over-expressed in cancer and diabetes. The enzymatic evaluation highlighted compound 1a as selective NPP1 inhibitor, however, 1c was observed as the most potent inhibitor of NPP1 with an IC50 value of 0.80 ± 0.04 μM. Compound 1l was found to be the most potent and moderately selective inhibitor of NPP3 (IC50 = 0.55 ± 0.01 μM). Furthermore, in vitro cytotoxicity assays of compounds 1a-m against MCF-7 and HT-29 cancer cell lines exhibited compound 1c (IC50 = 4.70 ± 0.67 μM), and 1h (IC50 = 1.58 ± 0.20 μM) as the most cytotoxic compounds against MCF-7 and HT-29 cancer cell lines, respectively. Both of the investigated compounds showed high degree of selectivity towards cancer cells than normal cells (WI-38). Molecular docking studies of selective and potent enzyme inhibitors revealed promising mode of interactions with important binding sites residues of both isozymes i.e., Thr256, His380, Lys255, Asn277 residues of NPP1 and His329, Thr205, and Leu239 residues of NPP3. In addition, the most potent antiproliferative agent, compound 1h, doesn't produce hypoglycemia as a side effect when injected to mice. This is an additional merit of the promising compound 1h.
- Ullah, Saif,El-Gamal, Mohammed I.,El-Gamal, Randa,Pelletier, Julie,Sévigny, Jean,Shehata, Mahmoud K.,Anbar, Hanan S.,Iqbal, Jamshed
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- Synthesis of magnetic chitosan supported metformin-Cu(II) complex as a recyclable catalyst for N-arylation of primary sulfonamides
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The application of chitosan, which has received much attention as a natural polymer and effective support, has many advantages such as biodegradability and biocompatibility. In this study, the immobilization of a copper complex on the magnetic chitosan bearing metformin ligand has been developed through immobilizing structurally defined metformin with long tail of (3-chloropropyl)trimethoxysilane (TMOS). The synthesized Fe3O4-chitosan@metformin-Cu(II) complex (Fe3O4-CS@Met-Cu(II)) was used as an effective, reusable and magnetic catalyst in the N-arylation of different derivatives of primary sulfonamides with arylboronic acids in ethanol. The primary sulfonamides were prepared from the reaction of sulfonyl chlorides with sodium cyanate in water under ultrasonic irradiation. Utilizing a wide variety of substrates in EtOH as a green solvent, high yields of the primary and secondary sulfonamides, easy work-up along with the excellent recovery and reusability of the catalyst, make this process a simple, economic and environmentally benign method. The synthesized Fe3O4-CS@Met-Cu(II) was characterized using various techniques such as XRD (X-ray diffraction), EDS (energy-dispersive X-ray spectroscopy), elemental mapping, TEM (transmission electron microscopy), FESEM (field emission scanning electron microscopy), VSM (vibrating sample magnetometer), ICP-MS (inductively coupled plasma mass spectroscopy), TGA (thermogravimetric analysis) and FT-IR (Fourier-transform infrared spectroscopy) analyses. The catalyst can be recycled and reused 5 times with no considerable loss of catalytic activity.
- Ahmadpoor, Fatemeh,Nasrollahzadeh, Mahmoud,Nezafat, Zahra,Pakzad, Khatereh
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- Development of succinimide-based inhibitors for the mitochondrial rhomboid protease PARL
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While the biochemistry of rhomboid proteases has been extensively studied since their discovery two decades ago, efforts to define the physiological roles of these enzymes are ongoing and would benefit from chemical probes that can be used to manipulate the functions of these proteins in their native settings. Here, we describe the use of activity-based protein profiling (ABPP) technology to conduct a targeted screen for small-molecule inhibitors of the mitochondrial rhomboid protease PARL, which plays a critical role in regulating mitophagy and cell death. We synthesized a series of succinimide-containing sulfonyl esters and sulfonamides and discovered that these compounds serve as inhibitors of PARL with the most potent sulfonamides having submicromolar affinity for the enzyme. A counterscreen against the bacterial rhomboid protease GlpG demonstrates that several of these compounds display selectivity for PARL over GlpG by as much as two orders of magnitude. Both the sulfonyl ester and sulfonamide scaffolds exhibit reversible binding and are able to engage PARL in mammalian cells. Collectively, our findings provide encouraging precedent for the development of PARL-selective inhibitors and establish N-[(arylsulfonyl)oxy]succinimides and N-arylsulfonylsuccinimides as new molecular scaffolds for inhibiting members of the rhomboid protease family.
- Andrews, Charlotte L.,Cardozo, Joaquin M.,Chow, Alyssa S.,Crainic, Jennifer A.,Parsons, William H.,Rutland, Nicholas T.,Sheehan, Brendan K.
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supporting information
(2021/08/04)
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- Unlocking Amides through Selective C–N Bond Cleavage: Allyl Bromide-Mediated Divergent Synthesis of Nitrogen-Containing Functional Groups
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We report a new set of reactions based on the unlocking of amides through simple treatment with allyl bromide, creating a common platform for accessing a diverse range of nitrogen-containing functional groups such as primary amides, sulfonamides, primary amines, N-acyl compounds (esters, thioesters, amides), and N-sulfonyl esters. The method has potential industrial applicability, as demonstrated through gram-scale syntheses in batch and in a continuous flow system.
- Govindan, Karthick,Chen, Nian-Qi,Chuang, Yu-Wei,Lin, Wei-Yu
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p. 9419 - 9424
(2021/11/30)
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- Synthesis of new Copper Catalyst with Pyrazole Based Tridentate Ligand and Study of Its Activity for Azide Alkyne Coupling
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Synthesis of new copper catalyst with pyrazole based tridentate ligand and study of its activity for azide alkyne coupling were investigated by researchers. To a solution of acetyl acetone (2.002 g, 20 mmol), 2- nitrophenylhydrazine in ethanol was added five drops of con. HCl and heated at 50° for 1 hour. After confirming the formation of 3, 5-dimethyl-1-(2-nitrophenyl)- 1H-pyrazole by TLC, ice cooled water was added in to the reaction mixture. The precipitate was filtered, washed with water and then hexane. The product formed as yellow precipitate, that precipitate had been filtered by normal filter paper. The product was recrystallized in ethanol. For synthesis, was suspended in 6 mL of deionized and stirred for 4 h until a clear solution was obtained in 50 ml round bottom flask Cu(OAc) 2. The reaction mixture was diluted with water, filtered, washed sequentially with water, methanol and n-hexane. Then dark greenish blue color crystal were formed and used for the reactions. The solid was crystallized in CH2Cl2 to get crystal whose structure was confirmed by single crystal XRD.
- Rajeswari, Panneer Selvam,Nagarajan, Rajendran,P, Sujith K,Emmanuvel, Lourdusamy
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supporting information
(2020/12/03)
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- Chromoselective Synthesis of Sulfonyl Chlorides and Sulfonamides with Potassium Poly(heptazine imide) Photocatalyst
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Among external stimuli used to promote a chemical reaction, photocatalysis possesses a unique one—light. Photons are traceless reagents that provide an exclusive opportunity to alter chemoselectivity of the photocatalytic reaction varying the color of incident light. This strategy may be implemented by using a sensitizer capable to activate a specific reaction pathway depending on the excitation light. Herein, we use potassium poly(heptazine imide) (K-PHI), a type of carbon nitride, to generate selectively three different products from S-arylthioacetates simply varying the excitation light and otherwise identical conditions. Namely, arylchlorides are produced under UV/purple, sulfonyl chlorides with blue/white, and diaryldisulfides at green to red light. A combination of the negatively charged polyanion, highly positive potential of the valence band, presence of intraband states, ability to sensitize singlet oxygen, and multi-electron transfer is shown to enable this chromoselective conversion of thioacetates.
- Antonietti, Markus,Guldi, Dirk M.,Markushyna, Yevheniia,Savateev, Aleksandr,Schü?lbauer, Christoph M.,Ullrich, Tobias
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supporting information
p. 20543 - 20550
(2021/08/12)
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- Efficient base-free hydrodehalogenation of organic halides catalyzed by a well-defined diphosphine-ruthenium(II) complex
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A base-free, robust catalytic system based on the diphosphine-ruthenium(II) complex cation has been developed for the hydrodehalogenation of a wide range of aryl- and alkyl-chlorides/bromides (27 examples) with molecule hydrogen. Notably, the reaction proceeds at 120 °C with low catalyst loading (0.1 mol%) and exhibits a good tolerance toward functional groups, such as amido, carboxyl, sulfonyl, methoxyl, ester groups. All dehalogenation products are confirmed by GC, GC–MS and NMR spectroscopy. Moreover, a mechanism for the diphosphine-ruthenium(II) complex cation catalyzed dehalogenation process has been proposed. This hydrodehalogenation methodology shows a potential application for the organic transformation and degradation of organic halides.
- Gao, Pengxiang,Liu, Qingbin,Liu, Yahuan,Ma, Ning,Wang, Zheng,Zhao, Ziwei
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- Synthesis of Sulfones and Sulfonyl Derivatives using Sodium (tert-butyldimethylsilyl)oxymethanesulfinate
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The present invention relates to a method for manufacturing a sulfone and sulfonyl derivative compound using sodium (tert-butyldimethylsilyl)oxymethanesulfinate, which is a novel organic sulfin salt, wherein the novel organic sulfin salt has good stability, environmental friendliness and economy, and is easy to handle, and thus significantly reduces the amount of transition metal catalysts and the amount of organic sulfin salts used when introducing aryl or alkenyl. Also, alkylation, arylation, amination, and fluorination are all possible during secondary functionalization. Therefore, the present invention can be usefully used in preparation and mass production of various kinds of sulfones and derivatives thereof including asymmetric sulfone derivatives.
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Paragraph 0967; 0977-0980
(2021/04/29)
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- Palladium-Catalyzed ortho-Benzoylation of Sulfonamides through C?H Activation: Expedient Synthesis of Cyclic N-Sulfonyl Ketimines
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The ortho-carbonylation of sulfonylarenes by non-hazardous aryl aldehydes as a carbonyl precursor was reported. In this method, the sulfonamide group serves as a directing group for C?H activation in the presence of a Pd catalyst under ligand-free conditions. The scope of this strategy has been extended to the one-pot two-step synthesis of cyclic N-sulfonyl ketimines under mild reaction conditions. Our approach could be considered as an alternative by circumventing the use of highly reactive organolithium or Grignard reagents to access a wide range of biologically potent cyclic N-sulfonyl ketimines. (Figure presented.).
- Ojha, Subhadra,Panda, Niranjan
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p. 561 - 571
(2019/12/24)
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- Tetrahydropyridines via FeCl3-Catalyzed Carbonyl-Olefin Metathesis
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Herein we describe the application of Lewis-acid-catalyzed carbonyl-olefin metathesis toward the synthesis of substituted tetrahydropyridines from commercially available amino acids as chiral pool reagents. This strategy relies on FeCl3 as an inexpensive and environmentally benign catalyst and enables access to a variety of substituted tetrahydropyridines under mild reaction conditions. The reaction proceeds with complete stereoretention and is viable for a variety of natural and unnatural amino acids to provide the corresponding tetrahydropyridines in up to 99% yield.
- Gaviria, Mario A.,Groso, Emilia J.,Richardson, Alistair D.,Rykaczewski, Katie A.,Schindler, Corinna S.,Vonesh, Hannah L.,Zehnder, Troy E.
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supporting information
(2020/04/02)
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- Synthesis of N-substituted sulfonamides containing perhalopyridine moiety as bio-active candidates
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A series of new halogenated aryl sulfonamides, as bio-active candidates, was synthesized from the reaction of the corresponding aryl sulfonamides with pentafluoro- and pentachloropyridines. Surprisingly, unlike aryl sulfonamides, the reaction of sulfamides with pentafluoro- and pentachloropyridines gave unexpected bis-perfluoro(chloro)pyridin-4-ylamines.
- Hosseini, Raziyeh,Mohammadiannejad, Kazem,Ranjbar-Karimi, Reza
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- New allyldithiocarbimate salts: Synthesis, structure and antifungal activity
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Fifteen new allyldithiocarbimates were prepared from different allylic bromides and various potassium dithiocarbimates, yielding (Z)-2-(methoxycarbonyl)-3-(X-nitrophenyl)allyl-(N-R-sulfonyl)dithiocarbimates (where X = 2, 3 and 4; R = phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl and 4-iodophenyl). These anions were isolated as tetraphenylphosphonium salts and characterized by HRMS, infrared, 1H and 13C NMR spectroscopies. Molecular electrostatic potentials were used to evaluate intermolecular interactions present in the new substances and to explain variations observed on their melting points. Single crystal X-ray diffraction experiments confirmed the Z stereochemistry of the allyldithiocarbimate anions. C–H?O, C–H?N, C–H?S and C–H?π intermolecular interactions in the solid state were studied by X-ray diffraction and Hirshfeld surface analyses. The new compounds inhibited the mycelial growth of various fungi species responsible for severe plant diseases. The allylithiocarbimates were especially active against Botrytis cinerea, with IC50 values as low as 20 μM, being more effective than the active principals of the commercial fungicides Ziram and Mancozeb.
- Albuini-Oliveira, Nathália M.,Alvarez, Natalia,Ellena, Javier,Guilardi, Silvana,Lima, Marcelo S.,Rubinger, Mayura M. M.,Souza, Rafael A. C.,Tavares, Eder C.,Vidigal, Antonio E. C.,Zacchi, Carlos H. C.,Zambolim, Laercio
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- Preparation and application of sulfanilamide and benzothiazole compounds containing tetrahydroisoquinoline
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The invention discloses a sulfanilamide compound, containing tetrahydroisoquinoline, shown as figure 1, and a benzothiazole compound, containing tetrahydroisoquinoline, shown as figure 2, and application of the sulfanilamide compound and the benzothiazole compound as novel protein arginine methyltransferase 5 inhibitors.
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Paragraph 0026-0027
(2020/04/17)
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- Synthesis and Biochemical Evaluation of Noncyclic Nucleotide Exchange Proteins Directly Activated by cAMP 1 (EPAC1) Regulators
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Exchange proteins directly activated by cAMP (EPAC) play a central role in various biological functions, and activation of the EPAC1 protein has shown potential benefits for the treatment of various human diseases. Herein, we report the synthesis and biochemical evaluation of a series of noncyclic nucleotide EPAC1 activators. Several potent EPAC1 binders were identified including 25g, 25q, 25n, 25u, 25e, and 25f, which promote EPAC1 guanine nucleotide exchange factor activity in vitro. These agonists can also activate EPAC1 protein in cells, where they exhibit excellent selectivity toward EPAC over protein kinase A and G protein-coupled receptors. Moreover, 25e, 25f, 25n, and 25u exhibited improved selectivity toward activation of EPAC1 over EPAC2 in cells. Of these, 25u was found to robustly inhibit IL-6-activated signal transducer and activator of transcription 3 (STAT3) and subsequent induction of the pro-inflammatory vascular cell adhesion molecule 1 (VCAM1) cell-adhesion protein. These novel EPAC1 activators may therefore act as useful pharmacological tools for elucidation of EPAC function and promising drug leads for the treatment of relevant human diseases.
- Wang, Pingyuan,Luchowska-Stańska, Urszula,Van Basten, Boy,Chen, Haiying,Liu, Zhiqing,Wiejak, Jolanta,Whelan, Padraic,Morgan, David,Lochhead, Emma,Barker, Graeme,Rehmann, Holger,Yarwood, Stephen J.,Zhou, Jia
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p. 5159 - 5184
(2020/06/03)
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- One-pot aerobic oxidative sulfonamidation of aromatic thiols with ammonia by a dual-functional β-MnO2 nanocatalyst
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High-surface-area β-MnO2 (β-MnO2-HS) nanoparticles could act as effective heterogeneous catalysts for the one-pot oxidative sulfonamidation of various aromatic and heteroaromatic thiols to the corresponding sulfonamides using molecular oxygen (O2) and ammonia (NH3) as respective oxygen and nitrogen sources, without the need for any additives.
- Hayashi, Eri,Yamaguchi, Yui,Kita, Yusuke,Kamata, Keigo,Hara, Michikazu
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supporting information
p. 2095 - 2098
(2020/02/26)
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- Efficient and Practical Synthesis of Sulfonamides Utilizing SO2 Gas Generated on Demand
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A simple and practical protocol was developed for the synthesis of sulfonamides by reacting organometallic reagents with SO2 gas generated on demand. SO2 was generated from readily available reagents safely in a highly contained and controlled fashion. The protocol allows the synthesis of sulfonamides without using either atom-inefficient SO2 surrogates or a SO2 cylinder that requires stringent storage regulations in the laboratory. The protocol was successfully applied to the synthesis of sildenafil.
- Chung Leung, Gulice Yiu,Ramalingam, Balamurugan,Loh, Gabriel,Chen, Anqi
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p. 546 - 554
(2020/04/22)
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- Rational Design, synthesis and biological evaluation of novel triazole derivatives as potent and selective PRMT5 inhibitors with antitumor activity
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Protein arginine methyltransferase 5 (PRMT5) is responsible for the mono-methylation and symmetric dimethylation of arginine, and its expression level and methyl transferring activity have been demonstrated to have a close relationship with tumorigenesis, development and poor clinical outcomes of human cancers. Two PRMT5 small molecule inhibitors (GSK3326595 and JNJ-64619178) have been put forward into clinical trials. Here, we describe the design, synthesis and biological evaluation of a series of novel, potent and selective PRMT5 inhibitors with antiproliferative activity against Z-138 mantle cell lymphoma cell line. Among them, compound C_4 exhibited the highest potency with enzymatic and cellular level IC50 values of 0.72 and 2.6 μM, respectively, and displayed more than 270-fold selectivity toward PRMT5 over several other isoenzymes (PRMT1, PRMT4 and PRMT6). Besides, C_4 demonstrated obvious cell apoptotic effect while reduced the cellular symmetric arginine dimethylation levels of SmD3 protein. The potency, small size, and synthetic accessibility of this compound class provide promising hit scaffold for medicinal chemists to further explore this series of PRMT5 inhibitors.
- Zhu, Kongkai,Shao, Jingwei,Tao, Hongrui,Yan, Xue,Luo, Cheng,Zhang, Hua,Duan, Wenhu
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p. 775 - 785
(2019/07/22)
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- Data-Driven Identification of Hydrogen Sulfide Scavengers
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Hydrogen sulfide (H2S) is an important signaling molecule whose up- and down-regulation have specific biological consequences. Although significant advances in H2S up-regulation, by the development of H2S donors, have been achieved in recent years, precise H2S down-regulation is still challenging. The lack of potent/specific inhibitors for H2S-producing enzymes contributes to this problem. We expect the development of H2S scavengers is an alternative approach to address this problem. Since chemical sensors and scavengers of H2S share the same criteria, we constructed a H2S sensor database, which summarizes key parameters of reported sensors. Data-driven analysis led to the selection of 30 potential compounds. Further evaluation of these compounds identified a group of promising scavengers, based on the sulfonyl azide template. The efficiency of these scavengers in in vitro and in vivo experiments was demonstrated.
- Yang, Chun-tao,Wang, Yingying,Marutani, Eizo,Ida, Tomoaki,Ni, Xiang,Xu, Shi,Chen, Wei,Zhang, Hui,Akaike, Takaaki,Ichinose, Fumito,Xian, Ming
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supporting information
p. 10898 - 10902
(2019/07/18)
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- Catalyst-Controlled Dual Reactivity of Sulfonimidamides: Synthesis of Propargylamines and N-Propargyl Sulfonimidamides
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Sulfonimidamides (SIAs) are acting both as surrogate amines and nucleophiles depending on the reaction conditions to access propargylamines and N-propargyl SIAs, respectively. The amine part of SIAs has been cleaved in an InCl3-catalyzed three-component A3 coupling reaction with aldehyde and acetylene to yield propargylamine. Moreover, N-propargyl SIAs were obtained via the direct-imination of propargyl alcohols in the presence of BF3?OEt2.
- Irfana Jesin,Nandi, Ganesh Chandra
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p. 743 - 749
(2019/01/04)
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- Synthesis of Sulfonimidamides from Sulfenamides via an Alkoxy-amino-λ6-sulfanenitrile Intermediate
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Sulfonimidamides are intriguing new motifs for medicinal and agrochemistry, and provide attractive bioisosteres for sulfonamides. However, there remain few operationally simple methods for their preparation. Here, the synthesis of NH-sulfonimidamides is achieved directly from sulfenamides, themselves readily formed in one step from amines and disulfides. A highly chemoselective and one-pot NH and O transfer is developed, mediated by PhIO in iPrOH, using ammonium carbamate as the NH source, and in the presence of 1 equivalent of acetic acid. A wide range of functional groups are tolerated under the developed reaction conditions, which also enables the functionalization of the antidepressants desipramine and fluoxetine and the preparation of an aza analogue of the drug probenecid. The reaction is shown to proceed via different and concurrent mechanistic pathways, including the formation of novel S≡N sulfanenitrile species as intermediates. Several alkoxy-amino-λ6-sulfanenitriles are prepared with different alcohols, and shown to be alkylating agents to a range of nucleophiles.
- Briggs, Edward L.,Tota, Arianna,Colella, Marco,Degennaro, Leonardo,Luisi, Renzo,Bull, James A.
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supporting information
p. 14303 - 14310
(2019/09/06)
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- Sulfonamide Synthesis through Electrochemical Oxidative Coupling of Amines and Thiols
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Sulfonamides are key motifs in pharmaceuticals and agrochemicals, spurring the continuous development of novel and efficient synthetic methods to access these functional groups. Herein, we report an environmentally benign electrochemical method which enables the oxidative coupling between thiols and amines, two readily available and inexpensive commodity chemicals. The transformation is completely driven by electricity, does not require any sacrificial reagent or additional catalysts and can be carried out in only 5 min. Hydrogen is formed as a benign byproduct at the counter electrode. Owing to the mild reaction conditions, the reaction displays a broad substrate scope and functional group compatibility.
- Laudadio, Gabriele,Barmpoutsis, Efstathios,Schotten, Christiane,Struik, Lisa,Govaerts, Sebastian,Browne, Duncan L.,No?l, Timothy
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supporting information
(2019/04/16)
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- Sulfonamide Synthesis through Electrochemical Oxidative Coupling of Amines and Thiols
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Sulfonamides are key motifs in pharmaceuticals and agrochemicals, spurring the continuous development of novel and efficient synthetic methods to access these functional groups. Herein, we report an environmentally benign electrochemical method which enables the oxidative coupling between thiols and amines, two readily available and inexpensive commodity chemicals. The transformation is completely driven by electricity, does not require any sacrificial reagent or additional catalysts and can be carried out in only 5 min. Hydrogen is formed as a benign byproduct at the counter electrode. Owing to the mild reaction conditions, the reaction displays a broad substrate scope and functional group compatibility.
- Laudadio, Gabriele,Barmpoutsis, Efstathios,Schotten, Christiane,Struik, Lisa,Govaerts, Sebastian,Browne, Duncan L.,No?l, Timothy
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supporting information
p. 5664 - 5668
(2019/04/17)
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- Sulfonamide compound and synthesis method and application thereof
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The invention discloses a synthesis method of a sulfonamide compound represented in a formula (2). According to the method, diazonium salt is used as a reaction raw material, and under the action of an inorganic nitrogen reagent, an inorganic sulfur dioxide reagent, an additive and a phosphine reagent, the diazonium salt is reacted in a solvent at 60-100 DEG C to obtain various sulfonamide compounds. According to the method inorganic salt is used as a nitrogen atom source and a sulfur dioxide source under a metal-free catalytic condition to construct the sulfonamide compound through one step,thereby avoiding the conventional multi-step synthesis of sulfonamide by condensing unstable acid chloride and amine; and the developed sulfonamide synthesis method can be further applied to the synthesis of the arthritis drug celecoxib and the psychotropic drug sulpiride.
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Paragraph 0046-0049
(2019/04/02)
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- Implication of sulfonylurea derivatives as prospective inhibitors of human carbonic anhydrase II
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Selective carbonic anhydrase (CA) inhibitors have gained a lot of importance owing to the implication of specific isoforms of CA in certain diseases like glaucoma, leukemia, cystic fibrosis, and epilepsy. A novel class of sulfonylurea derivatives was synthesized from corresponding sulfonyl chlorides and amines. Compounds with different pendant moieties in the sulfonylurea derivatives show significant interactions with human carbonic anhydrase II (CAII). In vitro evaluation of the sulfonylurea derivatives revealed that three compounds possess admirable inhibitory activity against CAII. Compounds containing methyl (G2), isopropyl (G4) and o-tosyl (G5) groups displayed IC50 (109-137 μm) for CAII. Fluorescence binding and cytotoxicity studies revealed that these compounds are showing good binding affinity (18-34 μM) to CAII and non- toxic to human cells. Further, molecular docking studies of G2, G4 and G5 with CAII showed that these compounds fit nicely in the active site of CAII. Molecular dynamics simulation studies of these compounds complexed with CAII showed that essential interactions were maintained up to 50 ns of simulation. These results indicate the promising nature of the sulfonylurea scaffold towards CAII inhibition and opens scope of hit to-lead optimization for discovery of effective drugs against CAII-associated disorders.
- Idrees, Danish,Hadianawala, Murtuza,Mahapatra, Amarjyoti Das,Datta, Bhaskar,Roy, Sonam,Ahamad, Shahzaib,Khan, Parvez,Imtaiyaz Hassan, Md.
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p. 961 - 969
(2018/05/23)
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- Diazabenzo[a]phenoxazone sulphonamides: synthesis, in-silico and in-vitro antimicrobial studies
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The syntheses of new sulphonamide derivatives of 8,10-diazabenzo[a]phenoxazones are reported. The condensation of 4,5-diamino-6-hydroxy-2-mercaptopyrimidine and 2,3-dichloro-1,4-naphthoquinone in a basic medium gave the key functional intermediate, 11-amino-6-chloro-9-mercapto-8,10-diazabenzo[a]phenoxazin-5-one. The conversion of the later compound to its sulphonamide derivatives was achieved via nickel catalyzed cross-coupling Buchwald-Hartwig protocol. Reaction between 11-amino-6-chloro-9-mercapto-8,10-diazabenzo[a]phenoxazin-5-one and various aryl sulphonamides and sulphonyl chlorides furnished eight new mono sulphonamide substituted diazaphenoxazone compounds. Subsequent coupling of mono sulphonamide substituted diazaphenoxazone compounds 5a-d with four different arylsulphonyl chlorides under similar reaction conditions gave the disubstituted derivatives 8a-d. The products were isolated in 74 – 88% yields and characterized by means of Uv-visible, FT-IR, 1H-NMR, 13C-NMR, and Mass spectroscopy. The synthesized compounds were screened for antimicrobial activity against bacterial strains: Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi and Klebsiella pneumonia, and fungal strains, Aspergillus niger, and Candida albican, using agar-well diffusion method. The activities of the compounds were compared with that of colymycin, which is a strong antibacterial, and antifungal drug, Most of the compounds showed appreciable antimicrobial activities comparable with the activity of colymycin. The in silico study revealed that all the synthesized compounds showed significant binding affinity for both intact and mutated DNA gyrase. Compounds 8a and 5b showed the highest binding affinities of -12.31 and -13.30 kcal/mol for intact and mutated DNA gyrase respectively.
- Ezeokonkwo, Mercy A.,Eze, Cosmas C.,Okafor, Sunday N.,Onoabedje, Efeturi A.,Godwin-Nwakwasi, Evelyn U.,Ibeanu, Fidelia N.
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p. 2482 - 2493
(2018/10/31)
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- Insight into sulfamethoxazole degradation, mechanism, and pathways by AgBr-BaMoO4 composite photocatalyst
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A composite photocatalyst, AgBr-BaMoO4 was fabricated by two step method; microwave hydrothermal and precipitation-deposition. The as prepared photocatalyst samples were characterized by various techniques. The facet coupling was seen between the (204) plane of BaMoO4 and (200)/(222) planes of AgBr on the basis of XRD/HRTEM analysis. The pharmaceutical pollutant, sulfamethoxazole was adopted to investigate the photocatalytic performances of samples under UV–vis irradiation. The AgBr-BaMoO4 composite degraded the aqueous sulfamethoxazole drug in UV–vis light about 64% within 75 min, which was attributed to efficient separation of photogenerated electron–hole pairs across the interface between Ag/AgBr and BaMoO4. The multi-electron induced oxygen reduced reaction (ORR) was observed. The radical trapping experiment indicates that OH? has major role for sulfamethoxazole degradation. The four successive photodegradation of sulfamethoxazole in UV–vis light indicates the stability of composite photocatalyst. Furthermore, the three different degradation pathways were designed on the basis of retention time and molecular masses of 18 degraded organic fragments that was confirmed by high-performance liquid chromatography photodiode array (HPLC-PDA) and high resolution-quadruple time of flight electrospray ionization mass spectroscopy (HR-QTOF ESI/MS) techniques. The total organic carbon (TOC) analysis suggested the mineralization of SMZ by composite photocatalyst. This study not only demonstrates the enhancement of photocatalytic performance of wide band gap semiconductor by making composite with narrow band gap semiconductor but also detail degradation pathways and mechanisms of sulfamethoxazole.
- Ray, Schindra Kumar,Dhakal, Dipesh,Lee, Soo Wohn
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p. 686 - 695
(2018/07/14)
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- Highly Chemoselective NH- and O-Transfer to Thiols Using Hypervalent Iodine Reagents: Synthesis of Sulfonimidates and Sulfonamides
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Aryl thiols can be selectively converted to sulfonimidates or sulfonamides with three new S-X connections being made selectively in one pot. Using hypervalent iodine reagents in the presence of ammonium carbamate, NH- and O-groups are transferred under mild and practical conditions. Reducing the loading of ammonium carbamate changed the product distribution, converting the sulfonimidate to the sulfonamide. Studies into the possible intermediate species are presented, suggesting that multiple pathways may be possible via sulfinate esters, or related intermediates, with each species forming the same products.
- Tota, Arianna,St John-Campbell, Sahra,Briggs, Edward L.,Estévez, Gala Ogalla,Afonso, Michelle,Degennaro, Leonardo,Luisi, Renzo,Bull, James A.
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supporting information
p. 2599 - 2602
(2018/05/22)
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- Behavior of IrCl3 as a Homogeneous Catalyst on the Oxidation of N-Acetylglucosamine in Acid Medium and Uncatalyzed Reaction in Alkaline Medium with Bromamine-B: Exploration of Kinetic, Mechanistic and Catalytic Chemistry
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Abstract: The experimental rate laws for the oxidation of N-acetylglucosamine with bromamine- B are: ? d[BAB]/dt = k/ [BAB]1 [GlcNAc]0.69 [HClO4]?0.76 [IrCl3]0.48 [BSA]?0.33 in acid medium and –d[BAB]/dt = k/?[BAB]1 [GlcNAc]1 [NaOH]0.79 in alkaline medium. The IrCl3 catalyzed reaction is thirteen fold faster than uncatalyzed reaction. Appropriate mechanisms and rate laws were deduced. Graphical Abstract: The reaction of N-acetylglucosamine with Bromamine-B in acid and alkaline medium is [Figure not available: see fulltext.].
- Shankarlingaiah, Dakshayani,Puttaswamy
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p. 424 - 437
(2017/11/29)
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- Development of Photoactivatable Nitroxyl (HNO) Donors Incorporating the (3-Hydroxy-2-naphthalenyl)methyl Phototrigger
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A new family of photoactivatable HNO donors of general structure RSO2NHO-PT [where PT represents the (3-hydroxy-2-naphthalenyl)methyl (3,2-HMN) phototrigger] has been developed, which rapidly releases HNO. Photogeneration of HNO was demonstrated using the vitamin B12 derivative aquacobalamin as a trapping agent. The amount of sulfonate RSO2– produced was essentially the same as the amount of HNO released upon photolysis, providing a convenient method to indirectly quantify HNO release. Two competing pathways were also observed; a pathway involving O–N bond cleavage leading to release of a sulfonamide, and a pathway resulting in release of the parent Nhydroxysulfonamide RSO2NHOH (for HNO donors with Me- and Ph-containing leaving groups only). Up to approximately 70 % of the HNO-generating pathway was observed with the CF3-containing leaving group, with HNO generation favored for small percentages of aqueous buffer in the acetonitrile/pH 7.00 phosphate buffer solvent mixture. Characterization of the photoproducts obtained from steady-state irradiation by NMR spectroscopy showed that the desired HNO-generating pathway was less favored for HNO donors with Me- and Ph-containing leaving groups compared to the CF3-containing leaving group, suggesting that the excellent CF3-containing leaving group promotes HNO generation.
- Zhou, Yang,Cink, Ruth B.,Fejedelem, Zachary A.,Cather Simpson,Seed, Alexander J.,Sampson, Paul,Brasch, Nicola E.
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p. 1745 - 1755
(2018/04/17)
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- Metal-free construction of primary sulfonamides through three diverse salts
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In this report, the first metal-free construction of primary sulfonamides through a direct three-component reaction of sodium metabisulfite, sodium azide and aryldiazonium has been established. Readily available inorganic Na2S2O5 and NaN3 were applied as the sulfur dioxide surrogate and nitrogen source respectively. The widely used sulfonamide drugs Celecoxib and Sulpiride, which possess multiple heteroatoms and active hydrogen containing functional groups, are efficiently installed with -SO2NH2 groups at a late stage. Control experiments and kinetic studies demonstrated that aryl radicals, sulfonyl radicals and conjugated phosphine imine radicals are involved in this transformation.
- Wang, Ming,Fan, Qiaoling,Jiang, Xuefeng
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supporting information
p. 5469 - 5473
(2019/01/03)
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- Glucose promoted facile reduction of azides to amines under aqueous alkaline conditions
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A quick and efficient method for the reduction of azides to amines in water using d-glucose and KOH as green reagents is reported. The protocol is simple, inexpensive, scalable, and can be applied to different aromatic, heteroaromatic and sulphonyl azides. A high level of chemoselectivity is observed for azide reduction in the presence of other reducible functionalities like cyano, nitro, ether, ketone, amide and acid. The reaction gets completed in a short time (5-20 minutes), and furnishes the amines in high yield (85-99%). Unlike conventional hydrogenations, this reduction protocol does not require any metal catalyst, elaborate experimental setup or use of high-pressure equipment.
- Chandna, Nisha,Kaur, Fatehjeet,Kumar, Shobhna,Jain, Nidhi
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p. 4268 - 4271
(2017/09/29)
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- The decomposition of benzenesulfonyl azide: A matrix isolation and computational study
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The thermal-decomposition and photo-decomposition of benzenesulfonyl azide, PhS(O)2N3, have been studied by combining matrix-isolation IR spectroscopy and quantum chemical calculations. Upon flash vacuum pyrolysis at 800 K, the azide splits off molecular nitrogen and exclusively furnishes phenylnitrene (PhN) and SO2 in the gas phase. In contrast, the azide favors stepwise photodecomposition in solid Ar and Ne matrices at 2.8 K. Specifically, the UV laser photolysis (193 and 266 nm) of PhS(O)2N3 results in the formation of the key nitrene intermediate PhS(O)2N in the triplet ground state, which undergoes pseudo-Curtius rearrangement into N-sulfonyl imine PhNSO2 under subsequent visible light irradiation (380-450 nm). Further fragmentation of PhNSO2 into SO2 and PhN followed by ring-expansion to didehydroazepine also occurs upon visible light irradiation. The preference of the stepwise mechanism for the decomposition of PhS(O)2N3 is supported by quantum chemical calculations using DFT B3LYP/6-311++G(3df,3pd) and CBS-QB3 methods.
- Deng, Guohai,Dong, Xuelin,Liu, Qifan,Li, Dingqing,Li, Hongmin,Sun, Qiao,Zeng, Xiaoqing
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p. 3792 - 3799
(2017/08/16)
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- THIAZOLIDINONE COMPOUNDS AND USE THEREOF
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A pharmaceutical composition containing a compound of Formula (I) for treating an opioid receptor-associated condition. Also disclosed is a method for treating an opioid receptor-associated condition using such a compound. Further disclosed are two sets of thiazolidinone compounds of formula (I): (i) compounds each having an enantiomeric excess greater than 90% and (ii) compounds each being substituted with deuterium.
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Paragraph 0054; 0417-0418; 0428-0429
(2017/09/21)
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- Transfer Hydro-dehalogenation of Organic Halides Catalyzed by Ruthenium(II) Complex
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A simple and efficient Ru(II)-catalyzed transfer hydro-dehalogenation of organic halides using 2-propanol solvent as the hydride source was reported. This methodology is applicable for hydro-dehalogenation of a variety of aromatic halides and α-haloesters and amides without additional ligand, and quantitative yields were achieved in many cases. The potential synthetic application of this method was demonstrated by efficient gram-scale transformation with catalyst loading as low as 0.5 mol %.
- You, Tingjie,Wang, Zhenrong,Chen, Jiajia,Xia, Yuanzhi
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p. 1340 - 1346
(2017/02/10)
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- Amide-Group-Directed Protonolysis of Cyclopropane: An Approach to 2,2-Disubstituted Pyrrolidines
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Regioselective protonolytic C-C bond cleavage of acylated aminomethyl cyclopropanes can be achieved using trifluoroacetic acid. The intermediate tertiary carbenium ion undergoes an intramolecular amination to give 2,2-substituted pyrrolidines. The strength of the acid and the amine substituent are important factors to achieve high regioselectivity, suggesting intramolecular proton transfer from the protonated amide function. Preliminary mechanistic studies revealed that cyclopropane cleavage proceeds with retention of configuration at the carbon to which the proton is attached. This observation is consistent with the "edge" protonation trajectory of the C-C bond.
- Skvorcova, Marija,Jirgensons, Aigars
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supporting information
p. 2478 - 2481
(2017/05/24)
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- Deep Eutectic Solvents as Reaction Media for the Palladium-Catalysed C?S Bond Formation: Scope and Mechanistic Studies
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A unique jigsaw catalytic system based on deep eutectic solvents and palladium nanoparticles where C?S bonds are formed from aryl boronic acids and sodium metabisulfite, is introduced. The functionalization step is compatible with a broad spectrum of reagents such as nucleophiles, electrophiles or radical scavengers. This versatile approach allows the formation of different types of products in an environmentally friendly medium by selecting the components of the reaction, which engage one with another as pieces in a jigsaw. This simple procedure avoids the use of toxic volatile organic solvents allowing the formation of complex molecules in a one-pot reaction under mild conditions. Despite the fact that only 1 mol % of metal loading is used, the recyclability of the catalytic system is possible. Kinetic experiments were performed and the reaction order for all reagents, catalyst and ligand was determined. The obtained results were compared to palladium nanocrystals of different known shapes in order to shed some light on the properties of the catalyst.
- Marset, Xavier,Guillena, Gabriela,Ramón, Diego J.
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supporting information
p. 10522 - 10526
(2017/08/10)
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- Silver(I)-Catalyzed Deprenylation of Allylsulfonamide Derivatives
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The silver(I)-catalyzed deprenylation of sulfonamide bearing prenyl functional groups on the nitrogen atom has been developed. In this reaction, the prenyl moiety was selectively eliminated without allyl or benzyl cleavage on the nitrogen atom. In addition, geranyl was also applicable for this elimination reaction. Furthermore, sulfonamide possessing two prenyl groups underwent a double deprenylation to form the corresponding deprenylated sulfonamide. Thus, a novel reactivity between the silver cation and double bond was observed.
- Inagaki, Fuyuhiko,Hira, Shisen,Mukai, Chisato
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p. 2143 - 2146
(2017/09/26)
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- Cu(II)-catalyzed decarboxylation/elimination of N-arylsulfonyl amino acids to primary aryl sulfonamides
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A novel protocol for CuO-catalyzed decarboxylation/elimination of N-arylsulfonyl amino acids was developed. It is the first example of using an accessible amino acid as an ammonia synthetic equivalent for the synthesis of primary aryl sulfonamides via oxidative decarboxylation/elimination reactions. The present protocol shows excellent functional group tolerance and provides an efficient method for the synthesis of primary aryl sulfonamides in excellent yields.
- Zhou, Liandi,Li, Xiaokang,Liu, Wei,Zhao, Yongli,Chen, Junmin
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p. 1299 - 1306
(2016/08/16)
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- Palladium(II)/copper(I)-catalyzed sequential C[sbnd]H arylation and oxidative C[sbnd]N bond cleavage of aryl sulfonamino acids: Efficient one-pot synthesis of primary biaryl sulfonamides
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A versatile strategy for the one-pot synthesis of primary biaryl-based sulfonamides has been developed via a tandem process consisting of palladium-catalyzed C[sbnd]H arylation and subsequent copper-catalyzed oxidative C[sbnd]N bond cleavage of aryl sulfonamino acids. Both electron-withdrawing and electron-donating functionalities can be introduced into the ortho positions of arenes bearing a variety of substituents. The amio acid moiety not only acts as a directing group but also as an ammonia synthetic equivalent. Importantly, the directing group was smoothly removed in the presence of catalytic CuI by using air as a sole oxidant.
- Liu, Wei,Zhao, Yongli,Yi, Fei,Chen, Junmin
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supporting information
p. 8382 - 8386
(2016/12/06)
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- Electrochemical Oxidative Amination of Sodium Sulfinates: Synthesis of Sulfonamides Mediated by NH4I as a Redox Catalyst
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An efficient protocol for the synthesis of sulfonamides via the electrochemical oxidative amination of sodium sulfinates has been developed. The chemistry proceeds in a simple undivided cell employing a substoichiometric amount of NH4I that serves both as a redox catalyst and a supporting electrolyte; in this manner additional conducting salt is not required. A wide range of substrates, including aliphatic or aromatic secondary and primary amines, as well as aqueous ammonia, proved to be compatible with the protocol. Scale-up was possible, thereby demonstrating the practicality of the approach. The electrolytic process avoids the utilization of external oxidants or corrosive molecular iodine and therefore represents an environmentally benign means by which to achieve the transformation.
- Jiang, Yang-Ye,Wang, Qing-Qing,Liang, Sen,Hu, Li-Ming,Little, R. Daniel,Zeng, Cheng-Chu
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p. 4713 - 4719
(2016/07/06)
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- A general iodine-mediated synthesis of primary sulfonamides from thiols and aqueous ammonia
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A general and efficient methodology for preparing primary sulfonamides has been developed. In the presence of iodine as the catalyst and TBHP (70% in water) as the oxidant, a wide range of primary sulfonamides were prepared from the corresponding thiols and aqueous ammonia in moderate to good yields.
- Feng, Jian-Bo,Wu, Xiao-Feng
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supporting information
p. 6951 - 6954
(2016/07/30)
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- METHOD OF FORMING CARBONYL COMPOUND AND DEPROTECTION METHOD OF AMIDE-BASED COMPOUND USING A CLEAVAGE REACTION OF CARBON-NITROGEN BOND
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The present invention relates to a preparation method of a carbonyl compound and a method for removing nitrogen-end protective group of an amide-based compound. The carbonyl compound is prepared by having a photocatalytic reaction of an amine-based group using water and an oxidizing agent. Therefore, the preparation method can prepare a carbonyl compound by usefully cutting carbon-nitrogen bonds at mild conditions, and such cutting reaction of carbon-nitrogen bonds can be usefully used for removing a protective group combined to an amide-based compound including amide or sulfonyl amide having carbon-nitrogen bonds.COPYRIGHT KIPO 2016
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Paragraph 0104; 0105; 0106; 0107
(2016/11/24)
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- Sulfonamide formation from sodium sulfinates and amines or ammonia under metal-free conditions at ambient temperature
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A novel, practical and highly efficient method for the construction of a variety of sulfonamides mediated by I2 was demonstrated. The reaction proceeds readily at room temperature using a variety of sodium sulfinates and amines or ammonia in water in a metal-, base-, ligand-, or additive-free protocol. Primary, secondary and tertiary sulfonamides were obtained in good to excellent yields with a broad range of functional group tolerability. This journal is
- Yang, Kai,Ke, Miaolin,Lin, Yuanguang,Song, Qiuling
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supporting information
p. 1395 - 1399
(2015/03/18)
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- Formation of Carbonyl Compounds from Amines through Oxidative C-N Bond Cleavage using Visible Light Photocatalysis and Applications to N-PMB-Amide Deprotection
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A method has been developed for C-N bond cleavage that utilizes visible light photocatalysis. The process, which utilizes 1 mol% of the ruthenium complex Ru(bpy)3Cl2 as the photocatalyst, potassium persulfate (K2S2O8) as the oxidant and water/acetonitrile (H2O/CH3CN) as the solvent, transforms a variety of primary, secondary and tertiary amines to the corresponding carbonyl compounds. In addition, this method was applied to the removal of a p-methoxylbenzyl (PMB) group from N-PMB protected amides.
- Iqbal, Naeem,Cho, Eun Jin
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supporting information
p. 2187 - 2192
(2015/07/27)
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- RuCl3 Catalyzed and Uncatalyzed Oxidative Decolorization of Acid Orange 7 Dye with Chloramine-B in Acid Medium: Spectrophotometric, Kinetic and Mechanistic Study
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Acid orange 7, chemically known as sodium 4-[(2E)-2-(2-oxonaphthalen-1-ylidene)hydrazinyl]benzenesulfonate, is extensively used for dyeing textiles, paper and leather. The discharge of wastewater containing this dye, causes environmental and health related problems. Therefore, in the present research, we have developed optimum conditions for the facile oxidative decolorization of this dye with sodium N-chlorobenzenesulfonamide or chloramine-B (CAB). The kinetics and mechanism of oxidative decolorization of acid orange 7 dye with CAB in acidic medium have also been studied spectrophotometrically at 303 K in the presence and absence of RuCl3 catalyst. Under similar experimental conditions, the reaction exhibits a first-order dependence of rate each on [CAB]o and [dye]o, and an inverse-fractional-order dependence on [H+] for both the RuCl3 catalyzed and uncatalyzed reactions. The order with respect to RuCl3 is fractional. Activation parameters have been computed. Dielectric effect is negative in both the cases. Oxidation products of the acid orange 7 dye are identified as 1,2-naphthoquinone and benzenesulfonic acid by GC-MS data. The RuCl3 catalyzed reaction is about four fold faster than the uncatalyzed reaction. The chemical oxygen demand value of the dye was determined. The mechanistic pathways and kinetic modelings have been computed based on experimental results. The developed oxidative decolorization method is expected to be helpful to treat acid orange 7 dye present in wastewater after suitable modifications. (Chemical Equation Presented).
- Manjunatha, Adalagere Somashekar,Puttaswamy
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p. 1312 - 1321
(2015/08/06)
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- Natural Indian Natrolite zeolite-supported Cu nanoparticles: A new and reusable heterogeneous catalyst for N-arylation of sulfonamides with boronic acids in water under ligand-free conditions
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We report here on the preparation of primary sulfonamides and efficient, easily recoverable and reusable copper nanoparticles supported on natural Indian Natrolite zeolite as a catalyst for arylation of sulfonamides with arylboronic acids in water. The catalyst was characterized using the powder XRD, SEM, EDS and FT-IR spectroscopy. The significant advantages of this methodology are high yields, elimination of organic solvents, and simple work-up procedure. The catalyst was easily isolated from the reaction mixture and reused with no significant loss in its activity.
- Azarifar, Davood,Soleimanei, Fatemeh
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p. 12119 - 12126
(2014/03/21)
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- Ruthenium trichloride catalyzed synthesis of 2,3-unsaturated-N-glycosides via Ferrier azaglycosylation
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An efficient, economical and mild protocol for the synthesis of 2,3-unsaturated-N-glycosides has been developed using ruthenium(III) chloride. The Ferrier azaglycosylation of glycals with various N-nucleophiles such as sulfonamides, benzamides, carbamates and N-substituted sulfonamides proceeded smoothly to afford the corresponding 2,3-unsaturated-N-glycosides or ‘N-pseudoglycals’ in good yields (64–98%). High α-anomeric selectivity was observed with N-substituted sulfonamides such as N-benzyl or N-phenyl sulfonamides under similar conditions.
- Reddy, Thurpu Raghavender,Chittela, Sravanthi,Kashyap, Sudhir
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supporting information
p. 9224 - 9229
(2017/09/08)
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- Oxidative debenzylation of N-benzyl amides and O-benzyl ethers using alkali metal bromide
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The oxidative debenzylation of N-benzyl amides and O-benzyl ethers was promoted with high efficiency by a bromo radical formed through the oxidation of bromide from alkali metal bromide under mild conditions. This reaction provided the corresponding amides from N-benzyl amides and carbonyl compounds from O-benzyl ethers in high yields.
- Moriyama, Katsuhiko,Nakamura, Yu,Togo, Hideo
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supporting information
p. 3812 - 3815
(2014/08/05)
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- In situ formation of vilsmeier reagents mediated by oxalyl chloride: A tool for the selective synthesis of N-sulfonylformamidines
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N-Sulfonylformamidines were produced from sulfonamides or N-acylated sulfonamides using Vilsmeier reagent obtained in situ from N,N-disubstituted formamides and oxalyl chloride. Optically active substrates did not racemize during the process. The efficient and mild cleavage of N-sulfonylformamidines can be achieved with hydrazine hydrate in ethanol. The entire procedure constitutes a simple method for protecting, and deprotecting, the sulfonamide moiety. A straightforward and efficient synthesis for N-sulfonylformamidines by employment of various Vilsmeier reagents generated in situ is described. The reactions proceed under mild reaction conditions and tolerate several sensitive functional groups. Copyright
- Gazvoda, Martin,Kocevar, Marijan,Polanc, Slovenko
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p. 5381 - 5386
(2013/09/02)
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