- Scalable electrochemical reduction of sulfoxides to sulfides
-
A scalable reduction of sulfoxides to sulfides in a sustainable way remains an unmet challenge. This report discloses an electrochemical reduction of sulfoxides on a large scale (>10 g) under mild reaction conditions. Sulfoxides are activated using a substoichiometric amount of the Lewis acid AlCl3, which could be regeneratedviaa combination of inexpensive aluminum anode with chloride anion. This deoxygenation process features a broad substrate scope, including acid-labile substrates and drug molecules.
- Kong, Zhenshuo,Pan, Chao,Li, Ming,Wen, Lirong,Guo, Weisi
-
supporting information
p. 2773 - 2777
(2021/04/21)
-
- Photocatalytic Deoxygenation of Sulfoxides Using Visible Light: Mechanistic Investigations and Synthetic Applications
-
The photocatalytic deoxygenation of sulfoxides to generate sulfides facilitated by either Ir[(dF(CF3)ppy)2(dtbbpy)]PF6 or fac-Ir(ppy)3 is reported. Mechanistic studies indicate that a radical chain mechanism operates, which proceeds via a phosphoranyl radical generated from a radical/polar crossover process. Initiation of the radical chain was found to proceed via two opposing photocatalytic quenching mechanisms, offering complementary reactivity. The mild nature of the radical deoxygenation process enables the reduction of a wide range of functionalized sulfoxides, including those containing acid-sensitive groups, in typically high isolated yields.
- Clarke, Aimee K.,Parkin, Alison,Rossi-Ashton, James A.,Taylor, Richard J. K.,Unsworth, William P.
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p. 5814 - 5820
(2020/07/21)
-
- Compound, preparation method thereof, medical intermediate and application thereof
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The invention relates to the technical field of chemical synthesis, and particularly discloses a compound, a preparation method thereof, a medical intermediate and an application thereof, the compoundcomprises the following raw materials: thioether, bromide and a proper amount of organic solvent, and the molar weight ratio of thioether to bromide is 1: (2-8). According to the compound provided bythe invention, thioether, bromide and a proper amount of organic solvent are used as raw materials, and the thioether compound can be obtained without adopting a catalyst, so that the problems of metal residues and the like are fundamentally eliminated, the provided preparation method is simple to operate, the method is simple in process and high in yield, the thioether compound is prepared through thioether metathesis reaction, metal catalysis is not needed in the whole reaction, meanwhile, the reaction condition is mild, the substrate range is wide, the problem of metal pollution existing in an existing thioether compound synthesis method is solved, and the method has wide market prospects in the fields of organic synthesis, medicine synthesis and the like.
- -
-
Paragraph 0043-0051; 0085-0124
(2020/08/06)
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- Sulfoxide Reduction/C(sp3)-S Metathesis Cascade in Ionic Liquid
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A sulfoxide reduction/C-S bond metathesis cascade between sulfoxides and alkyl bromides has been developed to access high-value sulfides without the use of any catalysts or bases. In this cascade, classical Kornblum oxidation is employed to reduce sulfoxides with alkyl bromides in ionic liquid. This protocol features high functional tolerance, mild conditions, promising scalability, and sustainable solvents.
- Liu, Chenjing,Chen, Dengfeng,Fu, Yuanyuan,Wang, Fei,Luo, Jinyue,Huang, Shenlin
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supporting information
p. 5701 - 5705
(2020/07/24)
-
- Rhodium-catalyzed Sommelet-Hauser type rearrangement of α-diazoimines: Synthesis of functionalized enamides
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An efficient rhodium catalyzed Sommelet-Hauser type rearrangement of sulfur ylides derived from α-thioesters and N-sulfonyl-1,2,3-triazoles has been successfully accomplished for the synthesis of various functionalized enamides. The developed reaction involves the unprecedented [2,3]-sigmatropic rearrangement of sulfur ylides with the imine motif. Importantly, the method works well with various substituted α-thioesters/-amides/-ketones and substituted N-sulfonyl-1,2,3-triazoles and allows the synthesis of diverse enamide derivatives in good to excellent yields. The reaction was also successfully extended to the one-pot synthesis of enamides from terminal alkynes.
- Anbarasan, Pazhamalai,Ramachandran, Kuppan,Reddy, Angula Chandra Shekar,Reddy, Palagulla Maheswar
-
supporting information
p. 5649 - 5652
(2020/06/09)
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- Gold-Catalyzed Oxidation of Thioalkynes to Form Phenylthio Ketene Derivatives via a Noncarbene Route
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Gold-catalyzed oxidations of thioalkynes with 8-methylquinoline oxides afford 2-phenylthioketenes that can be trapped efficiently with alcohols. The synthetic utility is manifested by terminal and internal thioalkynes over a wide scope, bearing esters, ke
- Sharma, Pankaj,Singh, Rahulkumar Rajmani,Giri, Sovan Sundar,Chen, Liang-Yu,Cheng, Mu-Jeng,Liu, Rai-Shung
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p. 5475 - 5479
(2019/08/01)
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- A Manganese N-Heterocyclic Carbene Catalyst for Reduction of Sulfoxides with Silanes
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The first reduction of sulfoxides catalysed by a well-defined manganese complex is described. A variety of sulfoxides are reduced to the corresponding sulfides in high yields using phenylsilane, diphenylsilane, and the economically feasible 1,1,3,3-tetramethyldisiloxane (TMDS) as reducing agents in the presence of a Mn-NHC complex. The reaction is performed under air and without the need of any additive. The involvement of radicals in the catalytic reaction is probed by spin-trap experiments.
- Sousa, Sara C. A.,Carrasco, Carlos J.,Pinto, Mara F.,Royo, Beatriz
-
p. 3839 - 3843
(2019/06/24)
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- Dealkylative intercepted rearrangement reactions of sulfur ylides
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Sulfur ylides are well-known to undergo sigmatropic rearrangement reaction. Herein, we describe a novel reactivity of sulfur ylides, which provides access to the product of a formal functional group metathesis upon dealkylative interception of the rearrangement process. Using a simple iron catalyst and in situ generated diazoalkanes this method provides access to α-mercaptoacetonitrile derivatives.
- Empel, Claire,Hock, Katharina J.,Koenigs, Rene M.
-
supporting information
p. 338 - 341
(2019/01/09)
-
- Rhodium-Catalyzed Rearrangement of S/Se-Ylides for the Synthesis of Substituted Vinylogous Carbonates
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An efficient rhodium-catalyzed unprecedented oxa-[2,3]-sigmatropic rearrangement of sulfur ylide derived from α-thioesters/ketones and diazo carbonyl compounds has been accomplished for the synthesis of various sulfur-tethered vinylogous carbonates in good to excellent yields. Important features of the developed reaction include wide functional group tolerance, excellent chemo- and regioselectivity, and efficient rearrangement involving the carbonyl motif. The present reaction also equally works well with α-selenoesters for the synthesis of seleno-containing vinylogous carbonates.
- Reddy, Angula Chandra Shekar,Anbarasan, Pazhamalai
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supporting information
p. 9965 - 9969
(2019/12/24)
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- Synthesis and computer-aided SAR studies for derivatives of phenoxyalkyl-1,3,5-triazine as the new potent ligands for serotonin receptors 5-HT6
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This research has provided the most active 5-HT6R agents among 1,3,5-triazine derivatives investigated to date and has also identified the world's first selenium-containing 5-HT6R ligands. The studies are focused on design, synthesis, biological evaluation and docking-supported SAR analysis for novel 5-HT6R agents as derivatives of lead structure 4-(4-methylpiperazin-1-yl)-6-(phenoxymethyl)-1,3,5-triazin-2-amine (7). The lead modifications included an introduction of: (i) various small substituents at benzene ring, (ii) a branched ether linker or (iii) the ether oxygen replacement with other chalcogen (S, Se) or sulfonyl moiety. Hence, a series of new compounds (7–24) was synthesized and examined on their affinities for 5-HT6R and selectivity, in respect to the 5-HT1AR, 5-HT2AR, 5-HT7R and dopamine D2 receptor, in the radioligand binding assays. For representative most active compounds functional bioassays and toxicity profile in vitro and antidepressant-like activity in vivo were examined. The 2-isopropyl-5-methylphenyl derivative (10) was found as the most active triazine 5-HT6R antagonist (Ki = 11 nM). SAR analysis indicated, that an exchange of oxygen to selenium (7 vs. 22), and especially, to sulfur (7 vs. 19) was beneficial to increase both affinity and antagonistic action for 5-HT6R. Surprisingly, an introduction of SO2 caused a drastic decrease of the 5-HT6R affinity, which was explained at a molecular level based on docking studies. All in vivo tested compounds (10, 18 and 21) did not show any risk of toxicity in the safety studies in vitro.
- Ali, Wesam,Wi?cek, Ma?gorzata,?a?ewska, Dorota,Kurczab, Rafa?,Jastrz?bska-Wi?sek, Magdalena,Sata?a, Grzegorz,Kucwaj-Brysz, Katarzyna,Lubelska, Annamaria,G?uch-Lutwin, Monika,Mordyl, Barbara,Siwek, Agata,Nasim, Muhammad Jawad,Partyka, Anna,Sudo?, Sylwia,Latacz, Gniewomir,Weso?owska, Anna,Kie?-Kononowicz, Katarzyna,Handzlik, Jadwiga
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supporting information
p. 740 - 751
(2019/06/24)
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- Asymmetric Catalytic [2,3] Stevens and Sommelet–Hauser Rearrangements of α-Diazo Pyrazoleamides with Sulfides
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Catalytic enantioselective [2,3] Stevens and Sommelet–Hauser rearrangements of α-diazo pyrazoleamides with sulfides were achieved by utilizing chiral N,N′-dioxide/nickel(II) complex catalysts. These rearrangements proceeded well under mild reac
- Lin, Xiaobin,Yang, Wei,Yang, Wenkun,Liu, Xiaohua,Feng, Xiaoming
-
supporting information
p. 13492 - 13498
(2019/08/28)
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- A 1 - benzyl - 6 - armor oxygen carbo- methyl tetrahydroisoquinoline derivatives, preparation method and application of the anti-platelet aggregation
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The invention belongs to the field of medicine synthesis, and provides a 1-benzyl-6-carbomethoxy methyl tetrahydroisoquinoline derivative, a preparation method and an application in resisting aggregation of thrombocyte, and particularly relates to a novel
- -
-
Paragraph 0030; 0044
(2018/04/21)
-
- Facile synthetic approaches to 1-thiocyclopropanecarboxylates
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Two facile synthetic approaches to the novel biologically interesting 1-thiocyclopropanecarboxylates starting from corresponding thiols were developed. Approach A involved five steps with the key steps being the SN2 reactions of thiols and α-br
- Zhang, Xiansheng,Wu, Jingwei,Liu, Yuqiang,Xie, Yafei,Liu, Changying,Wang, Jianwu,Zhao, Guilong
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p. 799 - 811
(2017/07/22)
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- A practical and chemoselective Mo-catalysed sulfoxide reduction protocol using a 3-mercaptopropyl-functionalized silica gel (MPS)
-
A convenient sulfoxide deoxygenation procedure using a mercaptopropyl-functionalized silica gel as the reducing agent is described. This new protocol based on a heterogeneous reagent displays broad scope and tolerance to reducible functional groups and, from an experimental point of view, enhances previous methods by simplifying the isolation of the sulfide to a simple filtration.
- García, Nuria,Fernández-Rodríguez, Manuel A.,García-García, Patricia,Pedrosa, María R.,Arnáiz, Francisco J.,Sanz, Roberto
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p. 27083 - 27086
(2016/03/25)
-
- Small Molecule Antagonists of the Nuclear Androgen Receptor for the Treatment of Castration-Resistant Prostate Cancer
-
After a high-throughput screening campaign identified thioether 1 as an antagonist of the nuclear androgen receptor, a zone model was developed for structure-activity relationship (SAR) purposes and analogues were synthesized and evaluated in a cell-based luciferase assay. A novel thioether isostere, cyclopropane (1S,2R)-27, showed the desired increased potency and structural properties (stereospecific SAR response, absence of a readily oxidized sulfur atom, low molecular weight, reduced number of flexible bonds and polar surface area, and drug-likeness score) in the prostate-specific antigen luciferase assay in C4-2-PSA-rl cells to qualify as a new lead structure for prostate cancer drug development.
- Johnson, James K.,Skoda, Erin M.,Zhou, Jianhua,Parrinello, Erica,Wang, Dan,O'Malley, Katherine,Eyer, Benjamin R.,Kazancioglu, Mustafa,Eisermann, Kurtis,Johnston, Paul A.,Nelson, Joel B.,Wang, Zhou,Wipf, Peter
-
supporting information
p. 785 - 790
(2016/08/24)
-
- Biomass derived β-cyclodextrin-SO3H as a solid acid catalyst for esterification of carboxylic acids with alcohols
-
A novel β-cyclodextrin-SO3H carbon based solid acid catalyst was prepared in a convenient and ecofriendly manner and was characterized using FTIR, PXRD, EDAX and NH3TPD to illustrate that the carbon material has been functionalized with -SO3H, -COOH and -OH groups. The catalyst was studied for esterification of various carboxylic acids and alcohols under solvent free conditions and showed excellent catalytic performance and gave good yields of esters in the range 78-99% at 70°C. No solvent was used either for catalyst preparation nor for esterification reaction. The catalyst can be easily recovered by simple filtration and reused for subsequent three runs without any significant impact on yields of products. The main advantage of this methodology is easy and ecofriendly catalyst preparation, easy catalyst separation, practical simplicity, safe reaction conditions, recyclable catalyst and high product yields.
- Thombal, Raju S.,Jadhav, Amol R.,Jadhav, Vrushali H.
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p. 12981 - 12986
(2015/02/19)
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- Oxo-rhenium(V) complexes containing heterocyclic ligands as catalysts for the reduction of sulfoxides
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This work reports the catalytic activity of a large variety of oxo-rhenium(V) complexes (1 mol-%) containing the ligands 2-(2-hydroxy-5- methylphenyl)benzotriazole (Hhmpbta), 2-(2-hydroxyphenyl)benzothiazole (Hhpbt), 2-(2-hydroxyphenyl)benzoxazole (Hhpbo), and 2-(2-hydroxyphenyl)-1H-benzimidazole (Hhpbi) in the deoxygenation of sulfoxides with silanes or boranes as the reducing agents. In general, all of the complexes are excellent catalysts, although the PhSiH3/[ReOBr2(hmpbta)(PPh3)] and pinacolborane/[ReOBr2(hmpbta)(PPh3)] systems are the most efficient for the reduction of aromatic and aliphatic sulfoxides and tolerate different functional groups. Copyright
- Sousa, Sara C. A.,Bernardo, Joana R.,Wolff, Mariusz,Machura, Barbara,Fernandes, Ana C.
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p. 1855 - 1859
(2014/04/03)
-
- Oxo-Rhenium(V) Complexes Containing Heterocyclic Ligands as Catalysts for the Reduction of Sulfoxides
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This work reports the catalytic activity of a large variety of oxo-rhenium(V) complexes (1 mol-%) containing the ligands 2-(2-hydroxy-5-methylphenyl)benzotriazole (Hhmpbta), 2-(2-hydroxyphenyl)benzothiazole (Hhpbt), 2-(2-hydroxyphenyl)benzoxazole (Hhpbo), and 2-(2-hydroxyphenyl)-1H-benzimidazole (Hhpbi) in the deoxygenation of sulfoxides with silanes or boranes as the reducing agents. In general, all of the complexes are excellent catalysts, although the PhSiH3/[ReOBr2(hmpbta)(PPh3)] and pinacolborane/[ReOBr2(hmpbta)(PPh3)] systems are the most efficient for the reduction of aromatic and aliphatic sulfoxides and tolerate different functional groups.
- Sousa, Sara C. A.,Bernardo, Joana R.,Wolff, Mariusz,Machura, Barbara,Fernandes, Ana C.
-
supporting information
p. 1855 - 1859
(2015/10/05)
-
- PYRAZOLO[3,4-D]PYRIMIDIN-4(5H)-ONE DERIVATIVES AS PDE9 INHIBITORS
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A compound of the general formula (I) wherein R1 is selected from the group consisting of phenyl unsubstituted or substituted with 1 to 3 substituents selected from F, Cl, Br, I, CN, -O-C1-C3-alkyl, fluorinated -O-C1-C3-alkyl, -(CH2)mOH and 5-membered heterocyclic group with 1 or 2 heteroatoms selected from N, O and S; and 6- or 10-membered heteroaryl with 1 to 3 heteroatoms selected from O, N and S; R2 and R3 independently of each other represent H atom or straight or branched C1-C3 alkyl; R4 is selected from the group consisting of 4- to 6- membered cycloalkyl, wherein one of carbon atoms can be replaced by O atom, and which is unsubstituted or substituted with one or two halogen atoms,and straight or branched C1-C4 alkyl; Q represents a bond or C1-C3-alkylene, which can be optionally substituted by one to three C1-C3-alkyls; X is selected from the group consisting of O, NR5, and S(O)p; R5 represents H atom or C1-C3alkyl; m is 1, 2 or 3; p is 0, 1 or 2; and salts thereof, for use as a medicament, in particular for treating cognitive function disorders and neurodegenerative diseases.
- -
-
Page/Page column 27
(2014/02/16)
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- Efficient synthetic approach to substituted benzo[b]furans and benzo[b]thiophenes by iodine-promoted cyclization of enaminones
-
An efficient synthetic approach to the substituted benzo[b]furan and benzo[b]thiophene scaffolds by iodine-mediated cyclization of the corresponding enaminones is described. This protocol was applied to a large series of these latter precursors to afford the respective benzoheterocycles substituted at the C-2 position by a carbonyl group functionality. A study of the factors that control this process reveals that the reactivity depends on the presence of electron-donor groups in the aryl ring of the aryloxycarbonylic and arylthiocarbonylic moieties.
- Labarrios, Ehecatl,Jerezano, Alberto,Jimenez, Fabiola,Del Carmen Cruz, Maria,Delgado, Francisco,Zepeda, L. Gerardo,Tamariz, Joaquin
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p. 954 - 971
(2014/08/05)
-
- Catalyst-free photoredox addition-cyclisations: Exploitation of natural synergy between aryl acetic acids and maleimide
-
Suitably functionalised carboxylic acids undergo a previously unknown photoredox reaction when irradiated with UVA in the presence of maleimide. Maleimide was found to synergistically act as a radical generating photoxidant and as a radical acceptor, negating the need for an extrinsic photoredox catalyst. Modest to excellent yields of the product chromenopyrroledione, thiochromenopyrroledione and pyrroloquinolinedione derivatives were obtained in thirteen preparative photolyses. In situ NMR spectroscopy was used to study each reaction. Reactant decay and product build-up were monitored, enabling reaction profiles to be plotted. A plausible mechanism, whereby photo-excited maleimide acts as an oxidant to generate a radical ion pair, has been postulated and is supported by UV/Vis. spectroscopy and DFT computations. The radical-cation reactive intermediates were also characterised in solution by EPR spectroscopy. UVA photolyses of aryloxy-, arylthio- and arylamino-acetic acids with maleimide yield oxa-, thia- and aza-tricyclo pyrroledione derivatives in the absence of a photoredox catalyst (see scheme). An intriguing mechanism has been proposed and has been supported and supplemented by NMR monitoring experiments, DFT computations and UV/Vis and EPR spectroscopy.
- Manley, David W.,Mills, Andrew,O'Rourke, Christopher,Slawin, Alexandra M. Z.,Walton, John C.
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supporting information
p. 5492 - 5500
(2014/05/20)
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- Highly efficient rhenium-catalyzed deoxygenation of sulfoxides without adding any reducing agent
-
This work reports a novel method for the deoxygenation of aromatic and aliphatic sulfoxides catalyzed by oxo-rhenium complexes without adding any reducing agent. The oxo-rhenium complex ReOCl3(PPh3) 2 proved to be very efficient for the deoxygenation of several sulfoxides with tolerance of different functional groups.
- Sousa, Sara C.A.,Bernardo, Joana R.,Rom?o, Carlos C.,Fernandes, Ana C.
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experimental part
p. 8194 - 8197
(2012/09/22)
-
- Pinacol as a new green reducing agent: Molybdenum-catalyzed chemoselective reduction of sulfoxides and nitroaromatics
-
Pinacol is disclosed as a new chemoselective and environmentally benign reducing agent for sulfoxides and nitroaromatics assisted by readily available dichlorodioxomolybdenum(VI) complexes as catalysts. A wide range of substrates including those bearing challenging functional groups has been efficiently and selectively reduced with acetone and water being the only by-products of these reactions. Copyright
- Garcia, Nuria,Garcia-Garcia, Patricia,Fernandez-Rodriguez, Manuel A.,Rubio, Ruben,Pedrosa, Maria R.,Arnaiz, Francisco J.,Sanz, Roberto
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supporting information; experimental part
p. 321 - 327
(2012/04/11)
-
- Cyanuric chloride as promoter for the oxidation of sulfides and deoxygenation of sulfoxides
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This Letter discusses the use of cyanuric chloride as an efficient promoter for the chemoselective oxidation of sulfides to the corresponding sulfones in the presence of H2O2 as the terminal oxidant. Sulfoxides were also found to undergo deoxygenation to sulfides with cyanuric chloride and potassium iodide system. The reaction is broad in scope and easy to perform.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Sohrabnezhad, Samira
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experimental part
p. 6420 - 6423
(2011/12/21)
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- Highly efficient gold nanoparticle catalyzed deoxygenation of amides, sulfoxides, and pyridine N-oxides
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Selective deoxygenation is one of the most important reactions in the areas of total synthesis, biological chemistry, and transformation of renewable biomass resources.To date, many useful methods for the selective deoxygenation of oxygen-containing organic molecules, such as amides, nitro compounds, epoxides, sulfoxides, and those with Noxide groups, have been developed. However, these methods often include stoichiometric reactions. Some successful catalysts have been reported,but most of them are homogeneous systems and still suffer from low activities and selectivities, harsh reaction conditions, and tedious workup procedures. Therefore, further development of highly efficient heterogeneous catalysts for selective deoxygenations is highly desired.
- Mikami, Yusuke,Noujima, Akifumi,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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experimental part
p. 1768 - 1772
(2011/03/21)
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- Reduction of sulfoxides catalyzed by oxo-complexes
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This work reports the catalytic activity of the oxo-complexes HReO 4, MoO2(acac)2, WO2Cl2, and VO(acac)2 in the reduction of sulfoxides with PhSiH3 or HBcat. The results obtained showed that the catalyst systems PhSiH 3/HReO4 (5 mol %) and HBcat/HReO4 (5 mol %) are highly efficient for the deoxygenation of sulfoxides. The complex MoO 2(acac)2 was also efficient, but the reactions required more time and heating. Finally, the complexes WO2Cl2 and VO(acac)2 showed a moderate activity.
- Cabrita, Ivania,Sousa, Sara C.A.,Fernandes, Ana C.
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experimental part
p. 6132 - 6135
(2010/12/24)
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- TAPC-promoted oxidation of sulfides and deoxygenation of sulfoxides
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Figure presented. 1,3,5-Triazo-2,4,6-triphosphorine-2,2,4,4,6,6- tetrachloride (TAPC) was found to be an efficient promoter for the oxidation of sulfides and deoxygenation of sulfoxides. Excellent yields, short reaction time, easy and quick isolation of the products, solvent-free process, and excellent chemoselectivity are the main advantages of this procedure.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Sheikh Arabi, Mehdi
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supporting information; experimental part
p. 6208 - 6213
(2010/11/04)
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- Highly efficient reduction of sulfoxides with the system borane/oxo-rhenium complexes
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This work reports the reduction of sulfoxides with boranes, in excellent yields, catalyzed by oxo-rhenium complexes (1 mol %) at room temperature under air atmosphere. The best results were obtained with catecholborane (HBcat) in the catalytic systems HBcat/ReIO2(PPh3)2, HBcat/Re2O7, and HBcat/MTO. DFT calculations were performed for the system based on ReIO2(PPh3)2, which was studied in more detail. The reaction starts with the formation of ReIO2(R2SO)2, followed by addition of the first molecule of HBcat and loss of R2S. In a second step, a second HBcat molecule attacks the Re(VII) intermediate, reducing the metal back to Re(V), while H2 and catBOBcat are released and the Re catalyst is regenerated, reentering the reaction cycle. The computed reaction barriers are much lower than those for any alternative pathway that could be envisaged.
- Fernandes, Ana C.,Fernandes, Jose A.,Romao, Carlos C.,Veiros, Luis F.,Calhorda, Maria Jose
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experimental part
p. 5517 - 5525
(2011/01/07)
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- Highly efficient and chemoselective reduction of sulfoxides using the system silane/oxo-rhenium complexes
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This work reports a novel method for the reduction of sulfoxides with silanes catalyzed by high valent oxo-rhenium(V) and (VII) complexes. The catalytic system PhSiH3/ReIO2(PPh3)2 (1 mol %) proved to be highly efficient for the reduction of a wide range of sulfoxides in excellent yields under mild conditions. This novel methodology is also highly chemoselective, tolerating several functional groups such as -CHO, -CO2R, -Cl, -NO2, and double or triple bonds.
- Sousa, Sara C.A.,Fernandes, Ana C.
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experimental part
p. 6872 - 6876
(2010/05/03)
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- Synthesis of corrosion preventive long-chain N-alkyl-2-(phenylthio)- acetohydrazides and 2-oxo-2-phenylethyl-2-alkanoylhydrazinecarbodithioates
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Long-chain N-alkyl-2-(phenylthio)acetohydrazides were synthesized via the reactions of 2-(phenylthio)acetohydrazide with long-straight-chain aldehydes and then reduction with sodium borohydride. The reactions of long-straight-chain hydrazides with carbon disulfide in alkaline media give the corresponding carbodithioate salts. Heating of potassium 2-alkanoylhydrazinecarbodithioates with phenacyl bromide do not yield cyclization and failed to give the corresponding long-chain thiazolidine-2-thiones, but gave the corresponding 2-oxo-2-phenylethyl-2-alkanoylhydrazinecarbodithioates via nucleophilic substitution reaction. In addition, the synthesized compounds were tested for their corrosion prevention capabilities in acidic or in mineral oil media.
- Yildirim, Ayhan,Cetin, Mehmet
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experimental part
p. 1279 - 1283
(2009/12/05)
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- Fully enzymatic resolution of chiral amines: Acylation and deacylation in the presence of Candida antarctica lipase B
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A fully enzymatic methodology for the resolution of chiral amines has been demonstrated. Candida antarctica lipase B (CaLB)-catalyzed acylation with N-methyl-and N-phenylglycine, as well as analogues having the general formula R1-X-CH2CO2R2 (R1 = Me, Ph; X = O, S) afforded the corresponding enantioenriched amides, which were subsequently enzymatically hydrolyzed. Surprisingly, CaLB also proved to be the catalyst of choice for this latter step. The heteroatom in the acyl donor profoundly influences both the enzymatic acylation and deacylation; the O-substituted reagents performed best with regard to enantioselectivity as well as reaction rate in synthesis and hydrolysis.
- Ismail, Hilda,Lau, Rute Madeira,Van Rantwijk, Fred,Sheldon, Roger A.
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experimental part
p. 1511 - 1516
(2009/08/07)
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- Mild and efficient deoxygenation of sulfoxides to sulfides with triflic anhydride/potassium iodide reagent system
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It was found that the combination of triflic anhydride/potassium iodide was an effective promoter for the deoxygenation of sulfoxides and gave the corresponding sulfides in excellent yield in acetonitrile at room temperature. It is worth mentioning that this reagent system is chemoselective and tolerates various functional groups, such as alkene, ketone, ester, aldehyde, acid, and oxime. Georg Thieme Verlag Stuttgart.
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Karimi, Ahmad
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experimental part
p. 2543 - 2546
(2009/04/04)
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- Reduction of sulfoxides with boranes catalyzed by MoO2Cl2
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The first example of an organic reduction with boranes catalyzed by a high valent oxo-complex is reported. The systems catecholborane/MoO2Cl2(H2O)2 (5 mol %) and BH3·THF/MoO2Cl2 (5 mol %) proved to be very efficient for the reduction of sulfoxides to the corresponding sulfides in excellent yields.
- Fernandes, Ana C.,Rom?o, Carlos C.
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p. 9176 - 9179
(2008/09/18)
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- A novel method for the reduction of sulfoxides and pyridine N-oxides with the system silane/MoO2Cl2
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A novel method for the reduction of sulfoxides and pyridine N-oxides using a silane and a catalytic amount of MoO2Cl2 in excellent yields and with a wide functional group tolerance is reported. A green protocol for this reaction was
- Fernandes, Ana C.,Rom?o, Carlos C.
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p. 9650 - 9654
(2007/10/03)
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- 6-Substituted pyrido-pyrimidines
-
The present invention provides compounds of the Formula I and II: wherein R1, R3, W, Z, X1, X2, Ar1, R8 and R9 are as defined herein, and methods and intermediates for their preparation and uses thereof.
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- N-acylsulfonamide apoptosis promoters
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N-Benzoyl arylsulfonamides having the formula are BCL-Xl inhibitors and are useful for promoting apoptosis. Also disclosed are BCL-Xl inhibiting compositions and methods of promoting apoptosis in a mammal.
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- N-Acylsulfonamide apoptosis promoters
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N-Benzoyl arylsulfonamides having the formula Are BCL-X1 inhibitors and are useful for promoting apoptosis. Also disclosed are BCL-X1 inhibiting compositions and methods of promoting apoptosis in a mammal.
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- Selective and mild oxidation of sulfides to sulfoxides by oxodiperoxo molybdenum complexes adsorbed onto silica gel
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Aliphatic and aromatic sulfides, ketosulfides, sulfinyl acids and esters, and olefinic sulfides were oxidized to sulfoxides using oxodiperoxo complexes of molybdenum coated on silica gel (150 ? pore size) in very high yields. Complete chemoselectivity was observed for the oxidation of all functional sulfides. Sulfones were, however, the main products of the reaction when the complexes were not coated on silica gel. The influence of silica gel as the support of these reactions was also investigated and it was demonstrated that it alters the reactivity of the complex but it is not responsible for the excellent chemoselectivity of the complexes. The complex [MoO(O2)2(pyrazole) (H2O)] proved to be more reactive than [MoO(O2)2(Opyr) (H2O)].
- Batigalhia, Fabiana,Zaldini-Hernandes, Marcelo,Ferreira, Ant?nio G,Malvestiti, Ivani,Cass, Quezia B
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p. 9669 - 9676
(2007/10/03)
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- Facile and efficient sulfenylation method using quinone mono-O,S-acetals under mild conditions
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A novel sulfenylation method induced by aromatization of quinone mono-O,S-acetals is described. These sulfenylation reagents readily react with silyl enolethers or electron rich aromatic compounds to give sulfenylation products under mild conditions. In particular, O,S-acetal 2j, which possesses a pentafluorophenylthio function, is the most effective reagent from the standpoint of the adaptability for various substrates.
- Matsugi,Murata,Gotanda,Nambu,Anilkumar,Matsumoto,Kita
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p. 2434 - 2441
(2007/10/03)
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- Synthetic utility of stannyl enolates as radical alkylating agents
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(Equation presented) The radical-initiated β-ketoalkylation of haloalkanes with tributylstannyl enolates is described. Stannyl enolates derived from aromatic ketones are reactive toward the homolytic β-ketoalkylation of simple haloalkanes as well as those activated by an electron-withdrawing group. The reactivity of stannyl enolates as radical alkylating agents can be utilized for an efficient three-component coupling reaction among stannyl enolates, haloalkanes, and electron-deficient alkenes.
- Miura, Katsukiyo,Fujisawa, Naoki,Saito, Hiroshi,Wang, Di,Hosomi, Akira
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p. 2591 - 2594
(2007/10/03)
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- Chemoselective deoxygenation of sulfoxides with titanium tetraiodide
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Chemoselective deoxygenation of sulfoxides was carried out using TiI4 as a reducing agent to give sulfides in good to excellent yields.
- Shimizu,Shibuya,Hayakawa
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p. 1437 - 1438
(2007/10/03)
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- Reaction of methyl diazoacetate with aldehydes, amines, thiols, alcohols and acids over transition metal-exchanged clays
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Metal-exchanged clays (M = Rh and Cu) catalyze effectively the reaction of methyl diazoacetate with various aldehydes, affording the corresponding β-keto esters in high yields. They have also been effective in the decomposition of methyl diazoacetate to form metallocarbenes which, in turn, successfully insert into X-H (X = N, O, S, CO2) bonds of a variety of amines, aldehydes, thiols and acids, thereby producing the corresponding esters. The Royal Society of Chemistry 1999.
- Phukan, Prodeep,Mohan, Jakkam Madan,Sudalai, Arumugam
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p. 3685 - 3689
(2007/10/03)
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- A novel efficient sulfenylation method using quinone mono-O,S-acetals under mild conditions
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A novel method for sulfenylation induced by aromatization of quinone mono-O,S-acetals is described.
- Matsugi, Masato,Gotanda, Kentoku,Murata, Kenji,Kita, Yasuyuki
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p. 1387 - 1388
(2007/10/03)
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- Pyrolysis of (2-Phenylethyl)phenylsulfonium Ylides
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In order to obtain information concerning the reaction mechanism of the pyrolysis of sulfonium ylides bearing a substituted phenyl group on the 2-position in the S-ethyl group of ethylphenylsulfonium ylide, (2-phenylethyl)phenylsulfonium bis(methoxycarbonyl)methylide (1) and dicyanomethylide(2) were subjected to pyrolysis in benzene.The reaction rates of 1 and 2 at 140 deg C were 6.0- and 3.2-times faster than those of ethylphenylsulfonium bis(methoxycarbonyl)methylide and dicyanomethylide, respectively.The activation parameters for 1 were ΔH++=125 kJ mol-1 and ΔS++=-3.8 JK-18mol-1, while those for 2 were ΔH++=124 kJ mol-1 and ΔS++=-2.5 JK-1 mol-1.Substituent efects on the β-phenyl groups in 1 and 2 afforded positive Hammett ρ-values: ρ = 0.49 (γ = 0.997) and ρ = 0.26 (γ = 0.993), respectively.From the obtained results, it was suggested that the pyrolysis proceeds through essentially a concerted intramolecular cis-elimination inclined toward a slightly carbanion-like type from an E1-like type by introducing a phenyl substituent at the 2-position of the ethyl group in the ethylphenylsulfonium ylide.
- Yoshimura, Toshiaki,Motoyama, Atsushi,Morishige, Akiko,Tsukurimichi, Eiichi,Shimasaki, Choichiro,Hasegawa, Kiyoshi
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p. 174 - 180
(2007/10/02)
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- A New Fragmentation Reaction of γ-Oxosulfonium Methylides
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Reactions of sulfonium methylides attached to a 5- or 6-membered cycloalkanone undergo the ring-fission as a major reaction course to give α-methylene-ω-(phenylthio)carboxylates, whereas sulfonium methylides attached to a larger ring give α-methylenecycloalkanones predominantly.Reactions of the acyclic compounds are also examined.
- Watanabe, Yoshihiko,Takeda, Toyonori,Anbo, Keiji,Ueno, Yoshio,Toru, Takeshi
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p. 159 - 162
(2007/10/02)
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- The Lawesson reagent as selective reducing agent for sulfoxides
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Different functionalized sulfoxides can be selectively deoxygenated by Lawesson reagent to yield the corresponding sulfides in high amounts.
- Bartsch,Erker
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p. 199 - 200
(2007/10/02)
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- Reactions of Arylsulphonyl, Arylthio and Acyl Acetates with S-Containing Heterocumulenes
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The reaction of arylsulphonyl- or (phenylthio)-acetates 1 with carbon disulphide in a basic medium led to the corresponding ketene dithioacetals 2 in good yields.The o-chloro derivative 1d gave with carbon disulphide various products under different reaction conditions.However, the reaction of 1 with phenyl isothiocyanate primarily resulted in N-substituted pyrimidone derivatives 9, except for 1e which mainly gave S,N-analogues of dithioacetals 10e and 10f. β-Ketoesters 1g, h also reacted with phenyl isothiocyanate to afford 5-acyl-2-thioxo-4-pyrimidones 9g, h.The dependency of the polarisation of the double bond in ketene dithioacetals and their S,N-analogues on acceptor groups was investigated with the help of 13C NMR spectroscopy.
- Chatterjee, Swapan K.,Rudorf, Wolf-Dieter
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p. 2916 - 2935
(2007/10/02)
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- Transition metal mediated thiation of aromatic rings
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Three appraoches to aromatic thiation have been studied. Dependent upon access to the necessary starting material, displacement of halogen in haloarenetricarbonylchromium(0) complexes by nucleophilic sulphur, quenching of lithiated arenetricarbonylchromium(0) complexes by electrophilic sulphur or palladium catalysed cross coupling of aryl iodides with alkylthiotrialkylstannanes were all effective and apparently general in scope. The latter is the preferred process.
- Dickens,Gilday,Mowlem,Widdowson
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p. 8621 - 8634
(2007/10/02)
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