- Highly efficient atom economical "green chemistry" synthesis of vinyl sulfides from thiols and acetylene in water
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Potassium thiolates generated by treatment of thiols with aqueous KOH react with acetylene to give the corresponding vinyl sulfides in 90-95% yields.
- Gusarova,Chernysheva,Yas'Ko,Trofimov
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Read Online
- Development of a highly efficient catalytic method for synthesis of vinyl ethers
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A new method for the preparation of alkyl vinyl ethers has been developed. Thus, various types of alkyl vinyl ethers were synthesized by the reaction of alcohols with vinyl acetate under the influence of a catalytic amount of [Ir(cod)Cl]2 combined with Na2CO3 in good to excellent yields. Copyright
- Okimoto, Yoshio,Sakaguchi, Satoshi,Ishii, Yasutaka
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Read Online
- A NaX zeolite framework containing magnetic MgFe2O4/CdO nanoparticles: Synthesis, characterization and catalytic performance in the decontamination of 2-chloroethyl phenyl sulfide (2-CEPS) as a model of sulfur mustard agent
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The present study highlights the successful fabrication of a zeolite NaX/MgFe2O4/CdO magnetically separable nanocomposite catalyst via an ultrasonic-assisted hydrothermal strategy for the decontamination of sulfur mustard agent simulant 2-chloroethyl phenyl sulfide (2-CEPS) for the first time. The as-fabricated nanocomposite was fully characterized using FESEM, TEM, EDAX, FTIR spectroscopy, XRD, AFM, VSM, N2-BET, and ICP-AES analyses. The decontamination process of 2-CEPS was monitored via GC-FID analysis. Furthermore, the effects of different analytical parameters such as contact time, catalyst type, catalyst amount and solvent type on the decontamination efficiency of 2-CEPS were precisely investigated. By using 50 mg of NaX/MgFe2O4/CdO catalyst in the presence of an n-heptane non-polar solvent, a decontamination efficiency of 100% was achieved after a contact time of 120 min. The decontamination process rate was verified by a first-order kinetic model. The obtained outcomes demonstrated that the apparent rate constant (kapp) and half-life time (t1/2) were 0.219 min-1 and 31.64 min, respectively. Lastly, the presence of hydrolysis and elimination products, namely 2-hydroxy ethyl phenyl sulfide (2-HEPS) and phenyl vinyl sulfide (PVS), from the effective degradation of 2-CEPS over the NaX/MgFe2O4/CdO catalyst was confirmed, and GC-MS analysis was performed to identify the degradation products of this agent simulant. This illustrates that the NaX/MgFe2O4/CdO catalyst could potentially be utilized for the removal of hazardous chemical warfare agents. This journal is
- Farhadi, Saeed,Sadeghi, Meysam,Zabardasti, Abedin
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supporting information
p. 21315 - 21326
(2021/12/04)
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- Electrophilic Chlorine from Chlorosulfonium Salts: A Highly Chemoselective Reduction of Sulfoxides
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Herein, we describe a selective late-stage deoxygenation of sulfoxides based on a novel application of chlorosulfonium salts and demonstrate a new process using these species generated in situ from sulfoxides as the source of electrophilic chlorine. The use of highly nucleophilic 1,3,5-trimethoxybenzene (TMB) as the reducing agent is described for the first time and applied in the deoxygenation of simple and functionalized sulfoxides. The method is easy to handle, economic, suitable for gram-scale operations, and readily applied for poly-functionalized molecules, as demonstrated with more than 45 examples, including commercial medicines and analogues. We also report the results of competition experiments that define the more reactive sulfoxide and we present a mechanistic proposal based on substrate and product observations.
- Acosta-Guzmán, Paola,Mahecha-Mahecha, Camilo,Gamba-Sánchez, Diego
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supporting information
p. 10348 - 10354
(2020/07/13)
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- Efficient hydrodeoxygenation of sulfoxides into sulfides under mild conditions using heterogeneous cobalt-molybdenum catalysts
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Nitrogen-doped carbon-supported cobalt-molybdenum bimetallic catalysts (abbreviated as Co-Mo/NC) are active for the hydrodeoxygenation of sulfoxides to sulfides under mild conditions (25-80 °C and 10 bar H2), which represents the first example of the use of heterogeneous non-noble metal catalysts for this transformation. MoO3 with Lewis acid sites assists the hydrodeoxygenation of sulfoxides into sulfides by hydrogen over cobalt nanoparticles.
- Yao, Kaiyue,Yuan, Ziliang,Jin, Shiwei,Chi, Quan,Liu, Bing,Huang, Renjie,Zhang, Zehui
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supporting information
p. 39 - 43
(2020/01/13)
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- Synthesis and characterization of TiO2/Mg(OH)2composites for catalytic degradation of CWA surrogates
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Surface catalyzed reactions can be a convenient way to deactivate toxic chemical warfare agents (CWAs) and remove them from the contaminated environment. In this study, pure titanium oxide, magnesium hydroxide, and their composites TiO2/Mg(OH2) were prepared by thermal decomposition and precipitation of the titanium peroxo-complex and/or magnesium nitrate in an aqueous solution. The as-prepared composites were examined by XRD, XPS, HRTEM, and nitrogen physisorption. Their decontamination ability was tested on CWA surrogates and determined by high-performance liquid chromatography (HPLC) and gas chromatography coupled with mass spectrometry (GC-MS). Dimethyl methyl phosphonate (DMMP) was used as a G simulant for the nerve agents sarin (GB) and soman (GD) while 2-chloroethyl ethyl sulfide (2-CEES) and 2-chloroethyl phenyl sulfide (2-CEPS) were used as surrogates of sulfur mustard (HD). The activity of the as-prepared composites was correlated with acid-base properties determined by potentiometric titrations and pyridine adsorption studied byin situDRIFTS. The mixing of Ti and Mg led to an increase of the surface area and the amount of surface -OH groups (with an increasing amount of Ti) that caused improved degradation of DMMP.
- ?tastny, Martin,?tengl, Václav,Ederer, Jakub,Henych, Jirí,Issa, Gloria,Jano?, Pavel,Kormunda, Martin,Tolasz, Jakub
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p. 19542 - 19552
(2020/06/04)
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- Extended Pummerer fragmentation mediated by carbon dioxide and cyanide
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Pummerer rearrangement reactions generate sulfur (II) oxidation state from sulfur (IV) starting materials in the presence of activating reagents. We found unprecedented transformation of vinyl sulfoxide; disulfide formation reactions mediated by atmospheric pressure of carbon dioxide in extended Pummerer rearrangement reactions. Only under CO2 atmosphere, we observed moderate to high yields of disulfide starting from sulfur (IV) starting materials. Investigations on the reaction mechanism revealed that the degradation of the starting materials and the products was significant in the absence of CO2. Further evidence for the suggested reaction mechanism was obtained by a cross-over experiment and a radical trapping reagent.
- Liu, Jian,Kragh, Rasmus R.,Kamounah, Fadhil S.,Lee, Ji-Woong
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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
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p. 3839 - 3843
(2019/06/24)
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- Safe and Metal-Free Synthesis of 1-Alkenyl Aryl Sulfides and Their Sulfones from Thiiranes and Diaryliodonium Salts
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A series of 1-alkenyl aryl sulfides was synthesized from thiiranes and diaryliodonium salts in tetrahydrofuran in the presence of potassium tert -butoxide. The proposed reaction mechanism involves generation of benzynes from the diaryliodonium salts in the presence of the base. Then, nucleophilic attack of the benzynes by thiiranes, followed by hydrogen abstraction and ring opening of the generated thiiranium intermediates, provides the sulfides. These sulfides were further oxidized with performic acid to the corresponding sulfones. The current method provides a metal-free and safe method for the preparation of 1-alkenyl aryl sulfides and their sulfones.
- Dong, Jun,Xu, Jiaxi
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p. 2407 - 2415
(2018/04/16)
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- Radical Hydroarylation of Functionalized Olefins and Mechanistic Investigation of Photocatalytic Pyridyl Radical Reactions
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We report the photoredox alkylation of halopyridines using functionalized alkene and alkyne building blocks. Selective single-electron reduction of the halogenated pyridines provides the corresponding heteroaryl radicals, which undergo anti-Markovnikov addition to the alkene substrates. The system is shown to be mild and tolerant of a variety of alkene and alkyne subtypes. A combination of computational and experimental studies support a mechanism involving proton-coupled electron transfer followed by medium-dependent alkene addition and rapid hydrogen atom transfer mediated by a polarity-reversal catalyst.
- Seath, Ciaran P.,Vogt, David B.,Xu, Zihao,Boyington, Allyson J.,Jui, Nathan T.
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supporting information
p. 15525 - 15534
(2018/11/23)
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- Difluoro- and trifluoro diazoalkanes-complementary approaches in batch and flow and their application in cycloaddition reactions
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Herein we report on applications of fluorinated diazoalkanes in cycloaddition reactions, with the emphasis on studying subtle differences between diverse fluorinated diazo compounds. These differences led to two major synthetic protocols in batch and flow that allow the safe and scalable synthesis of fluoroalkyl-, sulfone-substituted pyrazolines.
- Hock, Katharina J.,Mertens, Lucas,Metze, Friederike K.,Schmittmann, Clemens,Koenigs, Rene M.
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supporting information
p. 905 - 909
(2017/08/14)
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- Rapid and efficient deoxygenation of sulfoxides to sulfides with tantalum(V) chloride/sodium iodide system
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TaCl5/NaI system converts a wide range of sulfoxides to the corresponding sulfides in high yields with short reaction times, under mild conditions. It is worth mentioning that this protocol is chemoselective and tolerates various functional groups (such as –Br, –Cl, –OCH3, –CHO, and –NO2) and double bond.
- Yoo, Byung Woo,Park, Jeeyeon,Shin, Hyo Jong,Yoon, Cheol Min
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p. 597 - 603
(2017/10/06)
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- Platinum-supporting hollandite-type vanadium-chromium mixed oxides as efficient heterogeneous catalysts for deoxygenation of sulfoxides under atmospheric H2 pressure
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Deoxygenation of sulfoxides to their corresponding sulfides is an important reaction, and the development of efficient heterogeneous catalysts that can utilize molecular hydrogen (H2) as a reducing agent is highly desired. In this study, we successfully developed a new concept in heterogeneous catalysts, platinum-supporting hollandite-type vanadium-chromium mixed oxide catalysts (Pt/V(1-x)Crx-Hol, x: Cr/(V + Cr) molar ratio of the precursor solution), for sulfoxide deoxygenation with H2. Hollandite-type vanadium-chromium mixed oxides (V(1-x)Crx-Hol) that did not support platinum could stoichiometrically deoxygenate methyl phenyl sulfoxide to methyl phenyl sulfide, and the V3+ species in V(1-x)Crx-Hol were oxidized to V4+ after deoxygenation. However, the V4+ species could not be re-reduced with H2. By supporting platinum nanoparticles on V(1-x)Crx-Hol, the re-reduction of the oxidized vanadium species with H2 became possible. Thus, in the presence of Pt/V(1-x)Crx-Hol, catalytic sulfoxide deoxygenation with H2 as the reducing agent can be realized; the deoxygenation occurs on V(1-x)Crx-Hol, and the role of platinum is to re-reduce the oxidized vanadium species with H2. In the presence of Pt/V0.7Cr0.3-Hol, various types of structurally diverse sulfoxides could be selectively converted into their corresponding sulfides under atmospheric H2 pressure (1 atm). In addition, the present system was applicable to the deoxygenation of pyridine N-oxides to their corresponding pyridines. The observed catalysis was truly heterogeneous, and the Pt/V0.7Cr0.3-Hol catalyst could be reused for sulfoxide deoxygenation, although the performance was reduced.
- Uematsu, Tsubasa,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
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p. 1912 - 1920
(2017/07/15)
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- Synthesis of vinyl thioethers and bis-thioethenes from calcium carbide and disulfides
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Bis-thioethenes and vinyl thioethers were obtained from the reaction of disulfides and calcium carbide in good to high yields using a simple synthetic procedure and common laboratory setup. The tolerance of the reaction was investigated by the examples of aliphatic, aromatic, heteroaromatic and sesquiterpenic substrates.
- Rodygin, Konstantin S.,Gyrdymova, Yuliya V.,Zarubaev, Vladimir V.
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p. 476 - 478
(2017/10/05)
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- Photoredox catalysis for oxygenation/deoxygenation between sulfides and sulfoxides by visible-light-responsive polyoxometalates
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In this paper, we report the unique visible-light-responsive photoredox catalysis of a divacant lacunary silicotungstate TBA4H4[γ-SiW10O36] (SiW10) for functional group transformations of sulfur-containing compounds; namely, (i) aerobic oxygenation of sulfides to sulfoxides and (ii) deoxygenation of sulfoxides to sulfides. In the presence of suitable additives, such as Ce3+ (electron transfer mediator for oxygenation) and an alcohol (electron and proton donor for deoxygenation), SiW10 shows visible-light-induced charge transfers by using the newly formed highest occupied molecular orbitals derived from the coordinating Ce3+ or alcohol at the vacant site of SiW10. Consequently, oxygenation of sulfides and deoxygenation of sulfoxides can selectively proceed by irradiation with visible light (λ > 400 nm) to afford the corresponding desired products in high yields. The SiW10 photocatalysts can readily be recovered and reused for these transformations. Based on evidence from several experiments, the roles of the additives as well as the reaction mechanisms for these transformations are also discussed.
- Suzuki, Kosuke,Jeong, Jinu,Yamaguchi, Kazuya,Mizuno, Noritaka
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p. 1014 - 1021
(2016/02/19)
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- A mild, efficient, and selective procedure for the deoxygenation of sulfoxides with the TaCl5/indium system
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The TaCl5/In systemwas found to be a new reagent for reducing a wide range of structurally diverse sulfoxides to the corresponding sulfides with high yields under mild conditions. This protocol is chemoselective and tolerates several functional groups, such as Br, Cl, OCH3, CHO, and CH= CH2.
- Yoo, Byung Woo,Lee, Min Kyung,Yoon, Cheol Min
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p. 807 - 810
(2016/07/06)
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- An efficient metal-free pathway to vinyl thioesters with calcium carbide as the acetylene source
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Chemical reactions involving high-pressure acetylene are not easily performed in a standard laboratory setup. The risk of explosion and technical difficulties drastically complicate the equipment and greatly increase the cost. In this study, we propose th
- Rodygin, Konstantin S.,Ananikov, Valentine P.
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supporting information
p. 482 - 486
(2016/01/30)
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- Palladium-Catalyzed Synthesis of Aryl Vinyl Sulfides via 1,3-Oxathiolanes As Vinyl Sulfide Surrogates
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A nontraditional approach to synthesizing aryl vinyl sulfides is described. 2,2-Diphenyl-1,3-oxathiolane slowly liberates a vinyl sulfide anion under basic conditions. Using a Pd/Xantphos catalyst system to activate a wide range of aryl bromides, this transient sulfide species can be effectively trapped and fed into a traditional Pd0/PdII catalytic cycle. Scope and limitations of the methodology are presented along with significant discussion of a competitive C-S bond activation by this catalyst system.
- Schmink, Jason R.,Dockrey, Summer A. Baker,Zhang, Tianyi,Chebet, Naomi,Van Venrooy, Alexis,Sexton, Mary,Lew, Sarah I.,Chou, Steffany,Okazaki, Ami
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supporting information
p. 6360 - 6363
(2016/12/23)
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- A facile and efficient procedure for the deoxygenation of sulfoxides to sulfides with the HfCl4/Zn system
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Treatment of sulfoxides with the HfCl4/Zn system in acetonitrile at room temperature has been shown to provide the corresponding sulfides in high yields. This new methodology is highly chemoselective, tolerating several functional groups such as-Br,-Cl,-OCH3,-CHO and double bond.
- Yoo, Byung Woo,Yu, Bo Ran,Yoon, Cheol Min
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p. 358 - 363
(2015/06/22)
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- Aerobic addition of secondary phosphine oxides to vinyl sulfides: A shortcut to 1-hydroxy-2-(organosulfanyl)ethyl-(diorganyl)phosphine oxides
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Secondary phosphine oxides react with vinyl sulfides (both alkyl- and aryl-substituted sulfides) under aerobic and solvent-free conditions (80 °C, air, 7-30 h) to afford 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl)phosphine oxides in 70-93% yields.
- Malysheva, Svetlana F.,Artem'ev, Alexander V.,Gusarova, Nina K.,Belogorlova, Nataliya A.,Albanov, Alexander I.,Liu,Trofimov, Boris A.
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supporting information
p. 1985 - 1990
(2016/04/01)
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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)
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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.
- Sousa, Sara C. A.,Bernardo, Joana R.,Wolff, Mariusz,Machura, Barbara,Fernandes, Ana C.
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supporting information
p. 1855 - 1859
(2015/10/05)
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- A very useful and mild method for the deoxygenation of sulfoxide to sulfide with silica bromide as heterogeneous promoter
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Silica bromide (SB) as heterogeneous reagent and promoter is prepared from reaction of silica gel with PBr3 as a non-hydroscopic, filterable, cheap, and stable yellowish powder that can be stored for months. The results show that the SB is suitable and efficient reagent for deoxygenation of sulfoxides to the corresponding sulfides under mild conditions at room temperature. The easy availability of this reagent makes this simple procedure attractive and a practical alternative to the existing methods.
- Mohanazadeh, Farajollah,Veisi, Hojat,Sedrpoushan, Alireza,Zolfigol, Mohammad Ali,Golmohammad, Fereshteh,Hemmati, Saba,Hashemi, Majid
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- Photocatalytic deoxygenation of sulfoxides to sulfides over titanium(IV) oxide at room temperature without use of metal co-catalysts
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Deoxygenation of sulfoxides was examined in acetonitrile suspensions of metal-free titanium(IV) oxide (TiO2) under irradiation of UV light at room temperature. Experimental results indicate that deoxygenation was induced by the TiO2
- Kominami, Hiroshi,Nakanishi, Kousuke,Yamamoto, Satoshi,Imamura, Kazuya,Hashimoto, Keiji
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p. 100 - 103
(2014/07/08)
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- Photocatalytic deoxygenation of sulfoxides to sulfides over titanium(IV) oxide at room temperature without use of metal co-catalysts
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Deoxygenation of sulfoxides was examined in acetonitrile suspensions of metal-free titanium(IV) oxide (TiO2) under irradiation of UV light at room temperature. Experimental results indicate that deoxygenation was induced by the TiO2
- Kominami, Hiroshi,Nakanishi, Kousuke,Yamamoto, Satoshi,Imamura, Kazuya,Hashimoto, Keiji
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p. 100 - 103
(2015/03/18)
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- NaI/silica sulfuric acid as an efficient reducing system for deoxygenation of sulfoxides in poly ethylene glycol (PEG-200)
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Deoxygenation of structurally diverse sulfoxides including dialkyl, diaryl, aryl alkyl and allyl sulfoxides to the corresponding sulfides were carried out using a NaI/silica sulfuric acid reducing system at room temperature in poly ethylene glycol (PEG-200) in excellent yields.
- Zarei, Morteza,Ameri, Mohammad Aghil,Jamaleddini, Azar
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p. 259 - 263
(2013/08/26)
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- Selective and efficient deoxygenation of sulfoxides with NbCl 5/indium system
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It has been found that dialkyl, diaryl, and aryl alkyl sulfoxides can be selectively converted to the corresponding sulfides with a NbCl5/In system in good to excellent yields under mild conditions. Several functional groups (bromo, chloro, methoxy, aldehyde, and vinyl) were tolerated under the reaction conditions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Yoo, Byung Woo,Kim, Hyung Min,Kim, Duckil
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p. 2057 - 2061
(2013/06/26)
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- Reduction of sulfoxides and pyridine-N-oxides over iron powder with water as hydrogen source promoted by carbon dioxide
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A green process was developed for efficient reduction of sulfoxides and pyridine-N-oxides using the iron powder in the presence of H2O- CO2 to sulfides and pyridines, respectively. Notably, H2O is employed as the terminal hydrogen source, and CO2 could enhance hydrogen generation through in situ formation of carbonic acid. Thus carbonic acid offers simple neutralization by depressurizing CO2 and the system can eliminate unwanted byproducts. The high generality and chemo-selectivity of this protocol were demonstrated by the scope of substrates, in which chlorine, vinyl group and benzene ring can be tolerated.
- Ma, Ran,Liu, An-Hua,Huang, Cheng-Bin,Li, Xue-Dong,He, Liang-Nian
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supporting information
p. 1274 - 1279
(2013/06/05)
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- I 2 as a mild and efficient catalyst in deoxygenation of sulfoxides with thioacetic acid
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An effective procedure for deoxygenation of sulfoxides to sulfides using thioacetic acid as a reducing agent and a catalytic amount of I2 in MeCN at ambient temperature has been developed. Using this protocol, a variety of sulfoxides including benzyl, allyl, alkyl and aryl sulfoxides have been successfully reduced to the corresponding sulfides in excellent yields.
- Jabbari, Arida,Zarei, Morteza,Jamaleddini, Azar
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p. 413 - 418
(2012/10/29)
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- Unprecedented synthesis of iron-NHC complexes by C-H activation of imidazolium salts. Mild catalysts for reduction of sulfoxides
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A direct synthesis of bidentate cyclopentadienyl-functionalised NHC-iron(ii) complexes by using imidazolium salts and commercially available Fe3(CO)12 is developed. These well-defined iron-NHC complexes efficiently catalyse the reduction of sulfoxides under mild conditions. Radical scavenging experiments indicate the presence of free radicals in the catalytic reaction. The Royal Society of Chemistry 2012.
- Cardoso, Joao M.S.,Royo, Beatriz
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scheme or table
p. 4944 - 4946
(2012/06/01)
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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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- Mild and efficient deoxygenation of sulfoxides to sulfides with Cp 2TiCl2/gallium system
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The Cp2TiCl2/Ga system was found to be a new reagent for reducing a variety of sulfoxides to the corresponding sulfides in good to excellent yields under mild conditions. Copyright
- Yoo, Byung Woo,Min, Sang Ki
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experimental part
p. 2993 - 2996
(2011/09/14)
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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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- Pyrolysis of α- and β-heteroatoms substituted ethyl phenyl sulfoxides
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A study on the mechanism of the thermal decomposition of α- and β-heteroatoms substituted ethyl phenyl sulfoxides was carried out using 1-chloroethyl phenyl sulfoxide (1); two diastereomeric 1-acetoxyethyl (substituted phenyl) sulfoxides (2a) and (2b); and 2-chloroethyl phenyl, 2-bromoethyl phenyl, and 2-methoxyethyl phenyl sulfoxides (3, 4, 5). The rate of pyrolysis of 1 was 4.8 times faster at 160°C than that of ethyl phenyl sulfoxide used as a reference, while those of 2a and 2b were 107 and 155 times faster, respectively. The results indicate that the lone pair of electrons on the α-heteroatoms has a larger rate acceleration effect than the electronegativity of them. The substituent effects of the phenyl group of 2a and 2b gave positive Hammett ρ-values (ρa= 0.76 and ρb= 0.80 vs. σ). Activation parameters for 2a and 2b are as follows: 2a, ΔH?= 112 kJmol-1, ΔS?= -20 JK-1mol-1; 2b, ΔH?= 107 kJmol-1, ΔS?= -29 JK-1mol-1. Large deuterium kinetic isotope effects for 1-acetoxyethyl-2,2,2-d3 phenyl sulfoxides (2ad and 2bd) were observed (kH/kD= 3.5 ~ 4.1). These results suggest that the pyrolysis of -heteroatom substituted ethyl phenyl sulfoxides proceeds via a five-membered transition state deviated to E1-like in character. On the other hand, from the results of kinetics for the pyrolysis of 3, 4, and 5, no effect by the β-halogen atoms or some deceleration effect by the β-methoxy group was observed. Thus the reaction seems to proceed via an E1-like mechanism. Copyright Taylor & Francis Group.
- Yoshimura, Toshiaki,Sakae, Hironori,Yoshizawa, Masaki,Hasegawa, Kiyoshi,Tsukurimichi, Eiichi
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experimental part
p. 1162 - 1173
(2010/08/06)
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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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- Silica-PSCl3: A mild and efficient reagent for deoxygenation of sulfoxides
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A new solid supported reagent, silica-PSCl3, has been developed for deoxygenation of sulfoxides. With this reagent, conversion of sulfoxides to sulfides occurred cleanly and efficiently at room temperature. Facile isolation of the product was achieved by simple filtration of the by-products without any extensive workup. Copyright Taylor & Francis Group, LLC.
- Pandey, Lokesh Kumar,Pathak, Uma,Rao, A. Narasimha
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p. 4105 - 4109
(2008/03/13)
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- Mild and efficient deoxygenation of sulfoxides with MoCl5/indium system
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It has been demonstrated that dialkyl, diaryl, and aryl alkyl sulfoxides can be efficiently converted into the corresponding sulfides by the reaction with a MoCl5/In system in good to excellent yields under mild conditions. Copyright Taylor & Francis Group, LLC.
- Yoo, Byung Woo,Song, Min Suk,Park, Min Chol
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p. 3089 - 3093
(2008/02/12)
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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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- Microwave thermolysis: Part IX - A rapid reduction of sulphoxides with NaH2PO2 in dry media
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Reduction of a variety of sulphoxides using sodium hypophosphite under microwave irradiation is described. The method avoids the use of solvent and applicable for the variety of substrates.
- Meshram,Ganesh,Babu, K. Ramesh,Eeshwaraiah,Yadav
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p. 193 - 195
(2007/10/03)
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- A gentle and efficient route for the deoxygenation of sulfoxides using catecholborane (HBcat; cat = 1,2-O2C6H4)
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The addition of catecholborane (HBcat; cat = 1,2-O2C 6H4) to a wide range of sulfoxides affords the corresponding sulfides, dihydrogen, and catBOBcat. The addition of catecholborane (HBcat; cat = 1,2-O2C6H4) to a wide range of sulfoxides affords the corresponding sulfides, dihydrogen, and catBOBcat. The diboron compound catBOBcat acts like a Lewis acid and will coordinate one molecule of the starting sulfoxide. Although deoxygenations with bulky or electron withdrawing sulfoxides are slow, these reactions can be greatly accelerated with the use of excess HBcat or by employing a rhodium catalyst.
- Harrison, Daniel J.,Tam, Nga Chiu,Vogels, Christopher M.,Langler, Richard F.,Baker, R. Thomas,Decken, Andreas,Westcott, Stephen A.
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p. 8493 - 8496
(2007/10/03)
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- Selective deoxygenation of sulfoxides to sulfides with phosphites catalyzed by dichlorodioxomolybdenum(VI)
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Chemoselective deoxygenation of sulfoxides to sulfides was carried out by P(OPh)3 in mild conditions catalyzed by dichlorodioxomolybdenum(VI).
- Sanz, Roberto,Escribano, Jaime,Aguado, Rafael,Pedrosa, Maria R.,Arnaiz, Francisco J.
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p. 1629 - 1632
(2007/10/03)
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- Mild and efficient reduction of sulfoxides to sulfides with titanium tetrachloride-indium system
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TiCl4/In system was found to be a new reagent for reducing various sulfoxides to the corresponding sulfides in good yields under mild conditions.
- Yoo, Byung Woo,Choi, Kwang Hyun,Kim, Dong Yoon,Choi, Kyung Il,Kim, Joong Hyup
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- Mild and Efficient Reduction of Sulfoxides to Sulfides with Bis(cyclopentadienyl)titanium(IV) Dichloride-Indium System
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Cp2TiCl2/In system was found to be a new reagent for reducing various sulfoxides to the corresponding sulfides in good yield under mild and neutral conditions.
- Yoo, Byung Woo,Choi, Kwang Hyun,Lee, Sung Jae,Yoon, Cheol Min,Kim, Sung Hoon,Kim, Joong Hyup
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- New method for the synthesis of indenes
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A new two-step method was developed for the synthesis of 2-sulfonyl-substituted indenes from aromatic aldehydes. The reactions of 1-phenylsulfonyl-1-(trimethylsilyl)ethylene with ortho-lithiated derivatives of aromatic and heteroaromatic aldehydes afford conjugate addition products whose subsequent cyclization gives substituted 2-sulfonylindenes in preparative yields. The reactions of 2-(phenylsulfonyl)indenes with Grignard reagents were studied. It was shown that the sulfonyl group can be replaced in the presence of iron(III) acetylacetonate.
- Nenajdenko,Denisenko,Balenkova
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p. 2090 - 2096
(2007/10/03)
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- Process for synthesizing biaryl inhibitors of farnesyl-protein transferase
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The present invention is directed to a process for synthesizing 1,5 disubstituted imidazoles with biaryl components of the formula (I): which are usefull as Farnesyl-Protein Transferase inhibitors.
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- Regio- and stereospecific cleavage of α,β-epoxysilanes with lithium phenylsulfide
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Trimethyl- or dimethylphenylsilylepoxides react with lithium phenylsulfide to give regio- and stereodefined vinyl sulfides resulting from α-ring opening and Peterson elimination. When the epoxide bears the bulky tert-butyldiphenylsilyl group the reaction
- Cuadrado, Purificación,González-Nogal, Ana M.
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p. 1111 - 1114
(2007/10/03)
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- Synthesis and reactivity of novel ruthenium carbene catalysts. X-ray structures of [RuCl2(=CHSC6H5)(Pir 3)2] and [RuCl2(CHCH2CH2-C,N-2-C5H 4N)(Pir3)]
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Two novel classes of very air-stable ruthenium carbene complexes have been developed. The arylthio substituted ruthenium carbenes containing two bulky phosphines are deep purple solids, whereas the 2-pyridylethanyl substituted ruthenium carbene complexes contain only one bulky phosphine and are light-brown colored. One member of each class has been characterized with X-ray crystallography. The metathesis activity of these complexes has been investigated in the polymerization of dicyclopentadiene. Several excellent catalysts were identified. Desired geltimes and initiation temperatures could be easily tuned by changing the substitution pattern on the pendant ligand in the 2-pyridylethanyl substituted ruthenium carbenes.
- Van Der Schaaf, Paul A.,Kolly, Roman,Kirner, Hans-Jürg,Rime, Francois,Mühlebach, Andreas,Hafner, Andreas
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