- Air atmospheric photocatalytic oxidation by ultrathin C,N-TiO2nanosheets
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Herein, we demonstrate the highly efficient photocatalytic sulfide oxidation reaction under mild conditions,i.e.in air, at room temperature and in the absence of a sacrificial reagent, co-catalyst or redox mediator, by using ultrathin C,N-TiO2nanosheets as a photocatalyst.
- Cheng, Xiuyan,Zhang, Jianling,Liu, Lifei,Zheng, Lirong,Zhang, Fanyu,Duan, Ran,Sha, Yufei,Su, Zhuizhui,Xie, Fei
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supporting information
p. 1165 - 1170
(2021/02/26)
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- Tetrameric Lanthanide-Substituted Silicotungstate {Ln8Si4W40} Nanoclusters: Synthesis, Structural Characterization, Electrochemistry, and Catalytic Application for Oxidation of Thioethers
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All the title nanoclusters 1–10 with the molecular formula [(Ln2SiW10O38)4(W3O8)(OH)4(H2O)2]26? [LnIII =Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6), Er (7), Tm (8), Yb (9), and Y (10)] have been synthesized and isolated as mixed sodium and potassium salts. These nanoclusters are characterized by various analytical techniques such as FT-IR, UV/Vis, Photoluminescence, Single crystal X-ray diffraction, Electrochemistry, ICP-AES and Thermogravimetric analysis, and Powder X-ray diffraction. The {Ln8Si4W40} complexes show high efficiency and selectivity for the oxidation of thioethers using H2O2 as green oxidant. It is worth mentioning that the catalyst can be recovered even after five cycles of reaction with only a slight loss in its activity.
- Khan, Imran,Das, Vivek,Teillout, Anne-Lucie,Mbomekallé, Isra?l-Martyr,de Oliveira, Pedro,Sahoo, Subash Chandra,Hussain, Firasat
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supporting information
p. 1071 - 1081
(2021/03/16)
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- Electrolyte for rechargeable lithium battery and rechargeable lithium battery
-
An electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the electrolyte, the electrolyte including a non-aqueous organic solvent; a lithium salt; and an additive, wherein the additive includes a compound represented by Chemical Formula 1: wherein, in Chemical Formula 1, R is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C3 to C10 cycloalkenyl group, or a substituted or unsubstituted C6 to C20 aryl group, and n is an integer of 1 to 3.
- -
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Page/Page column 10
(2021/05/05)
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- Process for preparing 2 - (methylsulfonyl) - ethylene oxide and derivatives thereof
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The invention relates to 2 - (methylsulfonyl) - ethylene oxide and a preparation method thereof, belonging to the technical field of synthesis of ethylene oxide derivatives, and the method comprises the following steps: raw materials are vinyl methyl sulfone or allyl methyl sulfone 1:2:4 or methylallyl sulfonic acid ester. @timetimepieces are added dropwise to m-chloroperoxybenzoic acid by dropwise adding time of 30 min, 25 min, 10 min, heating reflux 15 - 30h and cooling to room temperature filtration. When the starting material is a vinyl methyl sulfone, the product is 2 - (methylsulfonyl) - ethylene oxide. When the starting material is allyl methyl sulfone, the product is methyl -2 and 3 - propylene oxide sulfonate. When the starting material is methylallyl sulfonate, the product is methyl -2 and 3 - epoxypropane sulfonate. The molar ratio of the raw material and the m-chloroperbenzoic acid is 1: (1.8 - 2.4). The preparation method is simple and high in yield.
- -
-
Paragraph 0034-0036; 0047-0049
(2021/09/29)
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- Synthesis of Na22[((RE)4(H2O)6Sb6O4)(SbW10O37)2(SbW8O31)2] [(RE)III = Y, Gd, Tb, Dy, Ho, Er, Tm, Yb]: Synthesis, characterization and catalytic application
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A series of eight rare-earth substituted antimony tungstates with the formulae [((RE)4(H2O)6Sb6O4)(SbW10O37)2(SbW8O31)2]22– [(RE)III = Y(1), Gd(2), Tb(3), Dy(4), Ho(5), Er(6), Tm(7), Yb(8)] has been synthesized under ambient conditions. The compounds were isolated using rare-earth salts and Na9[B-α-SbW9O33]?19.5 H2O as precursors along with sodium dihydrogen phosphate in 1 M NaCl solution. The addition of dihydrogen phosphate was found to be a crucial step for the isolation of these polyanions. The polyanions were characterized by various analytical techniques such as single crystal X-ray diffraction (1a – 6a) (SC-XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA). The compounds were found to show efficient heterogeneous catalytic activity for oxidation of thioethers.
- Gupta, Rakesh,Hussain, Firasat,Kaushik, Reetam,Khan, Imran
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- Synthesis and nano-Pd catalyzed chemoselective oxidation of symmetrical and unsymmetrical sulfides
-
A highly chemoselective, efficient and nano-Pd catalyzed protocol for the rapid construction of sulfoxides and sulfones via the oxidation of symmetrical and unsymmetrical sulfides using H2O2 as an oxidant has been developed, respectively. The ready availability of starting materials, easy recovery and reutilization of the catalyst, wide substrate scope, and high yields make this protocol an attractive alternative. The process also involves the metal-free and microwave-promoted synthesis of symmetrical diarylsulfides, and FeCl3-mediated preparation of symmetrical diaryldisulfides through the reaction of arenediazonium tetrafluoroborates with Na2S·9H2O as a sulfur source. In addition, unsymmetrical sulfides were generated via the K2CO3-mediated reaction of arenediazonium tetrafluoroborates with symmetrical disulfides.
- Li, Xing,Du, Jia,Zhang, Yongli,Chang, Honghong,Gao, Wenchao,Wei, Wenlong
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p. 3048 - 3055
(2019/03/21)
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- [MoO3(2,2″–bipy)]n catalyzed oxidation of amines and sulfides
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The polymeric catalyst [MoO3(2,2′–bipy)]n has been employed in the oxidation of secondary amines to nitrones, and sulfides to sulfoxides or sulfones, using tert–butylhydroperoxide (TBHP) as the stoichiometric oxidant. Whereas the oxi
- Tosi, Irene,Vurchio, Carolina,Abrantes, Marta,Gon?alves, Isabel S.,Pillinger, Martyn,Cavani, Fabrizio,Cordero, Franca M.,Brandi, Alberto
-
-
- Chiral Titanium(IV) Complexes Containing Polydentate Ligands Based on α-Pinene. Catalytic Activity in Sulfoxidation with Hydrogen Peroxide
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The reaction of TiCl4-n(OiPr)n (n = 0, 2, 4) with various terpenoid preligands based on α-pinene, C7H6Me3(OH)(NCH2CH2G) (G = NH2, I; NHMe, II; OH, III), stereoselectively affords a series of new chiral titanium(IV) complexes. Such complexes are either octahedral, [TiCl2X(OC7H6Me3NCH2CH2G-κ3N,N,O)] (X = Cl, G = NH2, 1; X = OiPr, G = NH2, 2; G = NHMe, 3), or trigonal bipyramidal, [Ti(OiPr)3(OC7H6Me3NCH2CH2G-κ2N,O)] (G = NH2, 4; NHMe, 5) and [TiX(OiPr)(OC7H6Me3NCH2CH2O-κ3N,O,O?)] (X = Cl, 6; OiPr, 8), depending on the acidity of titanium, the reaction conditions and the nature of the pendant ending group of the terpenoid ligand. Density functional theory (DFT) calculations have been carried out to assess the stability of the multiple possible diastereoisomers allowing us to propose structural suggestions. The new titanium complexes efficiently catalyze the selective oxidation of various types of sulfides to either sulfoxides or sulfones using aqueous hydrogen peroxide, under mild conditions. All compounds have been characterized by multinuclear NMR spectroscopy and the molecular structure for some of them has been determined by X-ray diffraction.
- Reviejo, Irene,Tabernero, Vanessa,Mosquera, Marta E. G.,Ramos, Javier,Cuenca, Tomás,Jiménez, Gerardo
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p. 3437 - 3449
(2018/10/31)
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- Synthesis of allyl sulfones from potassium allyltrifluoroborates
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Potassium allyltrifluoroborates underwent a bora-ene reaction with sulfur dioxide in the absence of Lewis acid catalysts to give sulfinyloxy-trifluoroborates, which subsequently undergo alkylation with electrophiles to produce sulfones in up to 91% yield. Benzyl halides and haloacetic acid derivatives can be used as the alkylation reagents while the Sanger reagent undergoes a SNAr reaction with sulfinyloxy-trifluoroborates to produce the corresponding 2,4-dinitrophenylsulfone. The developed method allows the transformation of potassium allyltrifluoroborates into allyl sulfones.
- Stikute, Agnese,Lugi?ina, Jevge?ija,Turks, Māris
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supporting information
p. 2727 - 2731
(2017/06/23)
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- Alkylimidazolium/alkylpyridinium octamolybdates catalyzed oxidation of sulfides to sulfoxides/sulfones with hydrogen peroxide
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β-Mo8O26 based alkyl imidazolium and pyridinium salts of general formula [Bmim]4Mo8O26 (Bmim = 1-butyl-3-methylimidazolium), [Hmim]4Mo8O26 (Hmim = 1-hexyl-3-methylimidazolium), [Dhmim]4Mo8O26 (Dhmim = 1.2-dimethyl-3-hexylimidazolium) and [Hpy]4Mo8O26 (Hpy = 1-hexylpyridinium) have been used as catalysts for the oxidation of sulfides using 30% hydrogen peroxide as oxidant. The examined β-Mo8O26 salts prove to be highly active and are self-separating. A high selectivity towards either sulfoxides or sulfones can be nicely controlled by variation of the reaction conditions. In both cases, the catalysts can be recycled and reused for several times without significant loss of activity, representing a good stability of the catalysts.
- Ye, Jin-Xin,Wang, Jing-Yun,Wang, Xin,Zhou, Ming-Dong
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supporting information
p. 1 - 3
(2016/04/26)
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- Selective sulfoxidation with hydrogen peroxide catalysed by a titanium catalyst
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A moisture-tolerant cyclopentadienyl-silsesquioxane titanium complex efficiently catalyses the selective oxidation of various types of sulfides to either sulfoxides (TOFs up to 32 530 h-1) or sulfones with H2O2 (30% in water) under mild conditions.
- Postigo, Lorena,Ventura, Maria,Cuenca, Toms,Jimnez, Gerardo,Royo, Beatriz
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p. 320 - 324
(2015/02/02)
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- One-pot synthesis of symmetric 1,7-dicarbonyl compounds via a tandem radical addition-elimination-addition reaction
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A novel approach to synthesize symmetric 1,7-dicarbonyl compounds via a tandem radical addition-elimination-addition reaction of S-carbonylmethyl xanthates with allylmethylsulfone and its analogues has been developed. Radicals were produced from S-carbonylmethyl xanthates by adding dilauroyl peroxide and reacted with allylmethylsulfone or analogues to generate terminal olefins as intermediates. The excessive radicals reacted with the intermediate olefins immediately to give adducts of symmetric 1,7-dicarbonyl compounds. This is an efficient method to synthesize 1,7-dicarbonyl compounds under mild conditions. The Royal Society of Chemistry 2013.
- Huang, Zhongyan,Xu, Jiaxi
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p. 15114 - 15120
(2013/09/02)
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- A peroxotungstate-ionic liquid brush assembly: An efficient and reusable catalyst for selectively oxidizing sulfides with aqueous H2O 2 solution in neat water
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An efficient and reusable heterogeneous catalytic assembly of peroxotungstate held in a ionic liquid (IL) brush was synthesized and an environmentally-friendly procedure was developed for selective oxidation of sulfides at room temperature using 30 wt.percent hydrogen peroxide as the terminal oxidant and water as a sole solvent. No organic co-solvent or other additive was needed. A 1.5-2.0 molpercent (based on W atom) loading catalyst was found to be sufficient for a smooth and clean reaction. Both aliphatic and aromatic sulfides were efficiently and selectively transformed into their respective sulfoxides or sulfones by simply controlling of equivalents of hydrogen peroxide. In addition to the high catalytic activity, the catalyst exhibits excellent chemoselectivity. Sensitive functional groups, such as double bond and hydroxyl, remained under the oxidation conditions the reaction even with an excess hydrogen peroxide. The catalyst was easily recovered (via simple filtration) and reused at least eight times without a noticeable loss of activity. ?2012 Sociedade Brasileira de Qui?mica.
- Shi, Xianying,Ma, Wenjuan,Ou, Hui,Han, Xiaoyan,Lu, Congmin,Chen, Yan,Wei, Junfa
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p. 1536 - 1542
(2012/11/07)
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- Peroxotungstates immobilized on multilayer ionic liquid brushes-modified silica as an efficient and reusable catalyst for selective oxidation of sulfides with H2O2
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Peroxotungstates held in a series of different supported ionic liquid brush catalysts were synthesized and characterized. Their catalytic performance towards the selective oxidation of sulfides with aqueous hydrogen peroxide was investigated under mild conditions. We found that the catalytic activities of the different catalysts depend on the number of supported ionic liquid layers and N-end-capped alkyl group on the imidazole ring. The highest yield of methyl phenyl sulfoxide was obtained using the BisILs-C8H17-W2 catalyst under optimum conditions. The sulfides were selectively oxidized to sulfoxides in high yields with trace sulfones detected by GC upon using 1.1 equivalents of H2O2. At 2.5 equivalents of H 2O2 the sulfones were found to be the main products. It is noteworthy that the catalyst resulted in high chemoselectivity towards sulfur groups with unsaturated double bonds even though excess hydrogen peroxide was used in addition to exhibiting high catalytic activity. There was no apparent loss of catalytic efficiency until the 8th cycle.
- Shi, Xianying,Han, Xiaoyan,Ma, Wenjuan,Wei, Junfa,Li, Jing,Zhang, Qiang,Chen, Zhanguo
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experimental part
p. 57 - 62
(2011/07/30)
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- Controlled oxidation of organic sulfides to sulfoxides under ambient conditions by a series of titanium isopropoxide complexes using environmentally benign H2O2 as an oxidant
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Controlled oxidation of organic sulfides to sulfoxides under ambient conditions has been achieved by a series of titanium isopropoxide complexes that use environmentally benign H2O2 as a primary oxidant. Specifically, the [N,N′-bis(2-oxo-3-R1-5-R2- phenylmethyl)-N,N′-bis(methylene-R3)-ethylenediamine]Ti(O iPr)2 [R1 = t-Bu, R2 = Me, R 3 = C7H5O2 (1b); R1 = R2 = t-Bu, R3 = C7H5O2 (2b); R1 = R2 = Cl, R3 = C7H 5O2 (3b) and R1 = R2 = Cl, R 3 = C6H5 (4b)] complexes efficiently catalyzed the sulfoxidation reactions of organic sulfides to sulfoxides at room temperature within 30 min of the reaction time using aqueous H2O 2 as an oxidant. A mechanistic pathway, modeled using density functional theory for a representative thioanisole substrate catalyzed by 4b, suggested that the reaction proceeds via a titanium peroxo intermediate 4c′, which displays an activation barrier of 22.5 kcal mol-1 (ΔG?) for the overall catalytic cycle in undergoing an attack by the S atom of the thioanisole substrate at its σ*-orbital of the peroxo moiety. The formation of the titanium peroxo intermediate was experimentally corroborated by a mild ionization atmospheric pressure chemical ionization (APCI) mass spectrometric technique. The Royal Society of Chemistry 2010.
- Panda, Manas K.,Shaikh, Mobin M.,Ghosh, Prasenjit
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experimental part
p. 2428 - 2440
(2010/06/18)
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- Linear-selective rhodium(I)-catalyzed addition of arylboronic acids to allyl sulfones
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One step further: The rhodium(I)-catalyzed addition of readily available arylboronic acids to allyl sulfones affords the linear (formal) hydroarylated products in good yields and excellent regioselectivities. The reaction broadens the scope of unactivated
- Tsui, Gavin C.,Lautens, Mark
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supporting information; experimental part
p. 8938 - 8941
(2011/02/21)
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- Selective and mild oxidation of sulfides to sulfoxides or sulfones using H2O2 and Cp′Mo(CO)3Cl as catalysts
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Dialkyl, aryl-alkyl, benzylic, and benzothiophenic sulfides are selectively oxidized to sulfoxides or sulfones, with stoichiometric amounts of H2O2 (aq) or TBHP, in the presence of complexes Cp′Mo(CO)3Cl, CpMoO2Cl and the mesoporous material MCM-41-2 as catalysts. The use of the thianthrene 5-oxide (SSO) probe shows that CpMo(CO)3Cl/H2O2 or TBHP are electrophilic oxidants (Xso ≤ 15). The same conclusion is drawn from competition experiments with a mixture of p-ClC6H4SCH3 and C6H5SOCH3.
- Gamelas, Carla A.,Louren?o, Tiago,da Costa, André Pontes,Simplício, Ana L.,Royo, Beatriz,Rom?o, Carlos C.
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p. 4708 - 4712
(2008/12/21)
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- In vivo metabolism of diallyl disulphide in the rat: Identification of two new metabolites
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1. Diallyl disulphide (DADS), a compound formed from the organosulphur compounds present in garlic, is known for its anticarcinogenic effects in animal models. 2. The aim was to identify and analyse the metabolites produced in vivo after a single oral administration of 200mgkg-1 DADS to rats. The organic sulphur metabolites present in the stomach, liver, plasma and urine were measured by gas chromatography coupled with mass spectrometry over 15 days. 3. Data indicate that DADS is absorbed and transformed into allyl mercaptan, allyl methyl sulphide, allyl methyl sulphoxide (AMSO) and allyl methyl sulphone (AMSO2), which are detected throughout the excretion period. Overall, the highest amounts of metabolites were measured 48-72 h after the DADS administration. AMSO2 is the most abundant and persistent of these compounds. The levels of all the sulphur compounds rapidly decline within the first week after administration and disappear during the second week. Only AMSO and AMSO2 are significantly excreted in urine. 4. These potential metabolites are thought to be active in the target tissues. Our data warrant further studies to check this hypothesis.
- Germain,Auger,Ginies,Siess,Teyssier
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p. 1127 - 1138
(2007/10/03)
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- One-pot, three-component synthesis of open-chain, polyfunctional sulfones
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Silyl enol ethers of esters, ketones, as well as allylstannane and allylsilanes react with sulfur dioxide activated with t-BuMe2SiOSO2CF3 to give silyl sulfinates that can be reacted in the same pot with a variety of electrophiles generating the corresponding polyfunctional sulfones. The silyl sulfinate intermediates are formed via ene-reactions following probably concerted mechanisms.
- Bouchez, Laure,Vogel, Pierre
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p. 225 - 231
(2007/10/03)
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- Aluminum chloride-iron promoted coupling of sulfonyl chlorides with alkyl halides in aqueous media
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A simple and inexpensive procedure for the coupling of sulfonyl chlorides and alkyl halides with aluminum chloride-iron system at ambient temperature in high yield is achieved in aqueous media.
- Saikia, Promod,Laskar, Dhrubojyoti D.,Prajapati, Dipak,Sandhu, Jagir S.
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p. 512 - 513
(2007/10/03)
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- Oxidation of thioethers and sulfoxides with hydrogen peroxide using TS-1 as catalyst
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A combined experimental and molecular simulation study of the oxidation of thioethers with H2O2 was conducted using titanium-containing zeolites as catalysts. Regioselectivity was investigated for the oxidation of allyl methyl thioether using TS-1 as catalyst. Only products for the oxidation of sulfur, such as sulfoxide and sulfolane, were found. Shape-selective oxidation was studied with four isomeric butyl methyl thioethers. For n-, iso-, and sec-butyl methyl thioethers, the principal product for the TS-1 catalyzed reaction was the sulfone, but that for tert-butyl methyl thioether was from partial oxidation to sulfoxide. The origin of this effect was evaluated using molecular simulations. Thioether oxidation to sulfoxide readily occurred via a non-catalyzed solution reaction, while the oxidation of sulfoxide to sulfone was only observed in the catalyzed reactions. The non-catalyzed reaction can be suppressed by conducting the catalyzed reaction in the presence of a base, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), that is too large to diffuse into the intracrystalline pore structure of TS-1. With DBU, the reaction rate with TS-1 as catalyst was much lower. The relative ratios of the sulfoxide and sulfone products can be elucidated through intramolecular steric hindrance and the shape selectivity of the zeolite. TS-1 has been used for the oxidation of alkenes, alcohols, allylic alcohols, phenols, and benzene.
- Hutchings,Lee,McMorn,Page,Robinson,Willock,Davies,Watson,McGuire,Lee,Bethell
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p. 1523 - 1529
(2007/10/03)
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- Chemoselective oxidation of sulfides to sulfones with magnesium monoperoxyphthalate (MMPP) on silica gel support in methylene chloride solvent
-
A simple, efficient and chemoselective, non-aqueous procedure for oxidation of sulfides to the corresponding sulfones with magnesium monoperoxyphthalate on hydrated silica gel has been developed.
- Ali, Mohammed Hashmat,Bohnert, Gary J.
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p. 2983 - 2998
(2007/10/03)
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- Bi or Cd-induced coupling of sulfonyl chlorides with allylic halides. A simple synthesis of allylic sulfones
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The bismuth or cadmium-catalyzed coupling reaction between aryl and alkyl sulfonyl chlorides and allylic halides proceeds smoothly to provide excellent yields of allylic sulfones at ambient temperature.
- Baruah, Mukulesh,Boruah, Anima,Prajapati, Dipak,Sandhu, Jagir S.
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p. 1083 - 1084
(2007/10/03)
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- Mild and Selective Oxygenation of Sulfides to Sulfoxides and Sulfones by Perfluoro-cis-2,3-dialkyloxaziridines
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Sulfides are oxidized to sulfoxides by stoichiometric amounts of perfluoro-cis-2,3-dialkyloxaziridines 2.The reactions proceed at -40 deg C with nearly complete selectivity and very good yields.Sulfoxides are also oxidized easily by 2 under mild conditions to corresponding sulfones.The oxidation of some bioactive sulfides (promazine, albendazole, biotin, and others) is also reported.
- DesMarteau, Darryl D.,Petrov, Viacheslav A.,Montanari, Vittorio,Pregnolato, Massimo,Resnati, Giuseppe
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p. 2762 - 2765
(2007/10/02)
-
- Structure-Stability Relationships in Unsaturated Sulfur Compounds. III. A Thermodynamic and 13C MNR Spectroscopic Study of the Conformations of Vinyl Sulfones
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The conformations of the stable rotamers of alkyl 1-propenyl sulfones have been studied in a thermodynamic and 13C NMR spectroscopic study.The most stable rotamer of the E isomer was found to have the anticlinal conformation.The Z isomer will probably adopt a nearly anticlinal conformation.
- Kimmelma, Reijo
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p. 1201 - 1206
(2007/10/02)
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- Chemoselective catalytic oxidation of sulfides to sulfones with tetrapropylammonium perruthenate (TPAP)
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Tetrapropylammonium perruthenate has been found to be an efficient catalyst for the conversion of sulfides to sulfones. The method is highly chemoselective and isolated double bonds are generally unaffected.
- Guertin,Kende
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p. 5369 - 5372
(2007/10/02)
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- Sulphonate Esters as Sources of Sulphonyl Radicals; Ring-closure Reactions of Alk-4- and -5-enesulphonyl Radicals
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Alkyl alkanesulphonates and arenesulphonates were found to be useful sources of sulphonyl radicals, particularly for spectroscopic work, when treated with organotin or organosilyl radicals.Allyl, propynyl and penta-2,4-dienyl methanesulphonates gave, however, allyl, propynyl and pentadienyl radicals, respectively.Sulphonyl radicals generated in this way added efficiently to alk-1-enes with electron-releasing substituents, and the EPR spectra of the adduct radicals were recorded.A variety of radical initiation systems were tried on pent-4-enesulphonyl chloride.The pent-4-enesulphonyl radical cyclised mainly in the endo mode to give the six-membered-ring sulphone.Similarly, the hex-5-enesulphonyl radical cyclised to give thiepane 1,1-dioxide, with a seven-membered ring.The cyclohex-2-enylethanesulphonyl radical cyclised mainly in the exo mode to give 2-chloro-9-thiabicyclononane 9,9-dioxide.The mechanisms of these reactions are discussed.
- Culshaw, Peter N.,Walton, John C.
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p. 1201 - 1208
(2007/10/02)
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- SH2' Type Reactions of Arenesulfonyl Chlorides with Allylic Compounds Catalyzed by a Ruthenium(II) Complex
-
In the presence of a catalytic amount of dichlorotris(triphenylphosphine)ruthenium(II), the reactions of arenesulfonyl chlorides with allyl phenyl sulfide and allyl phenyl selenide proceeded smoothly to give allyl phenyl sulfone in high yield as well as the corresponding diphenyl disulfide or diphenyl diselenide.An SH2'-type mechanism involving the arenesulfonyl radical is proposed.
- Kamigata, Nobumasa,Ishii, Kimiko,Ohtsuka, Takeshi,Matsuyama, Haruo
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p. 3479 - 3481
(2007/10/02)
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- Search for New Membrane-active Substances: Synthesis of Tropan-3-ols with Alkyl, Alkenyl and Alkenynyl Groups at the Bridgehead
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The synthesis of tropan-3-ols with alkyl, alkenyl and alkynyl groups at the bridgehead is described.The new compounds have been considered as new membrane-active substances that would serve as model compounds for histrionicotoxin (1).Application of the Noyori route to 2-substituted pyrroles was unsuccessful.In order to avoid difficulties in obtaining individual long-chain 4-keto aldehydes for the Robinson condensation of each new model compound a key tropane intermediate (8) was prepared instead.The first attempts to extend the chains of the mesyl ester of the diol (8b) and iodomethyltropanol (9b) by Grignard type coupling failed.Therefore we embarked on a Wittig reaction of the tropane-1-carbaldehyde (11) synthesized in high yield from the diol (8).Indeed, both pent-1-enyl- and pentyl-tropanols, (12) and (13) were obtained.Coupling with an acetylenic phosphorane led to the pent-1-enynyltropanol (14).A further new key compound, namely 3β-acetoxytropan-1-ylacetaldehyde (15) was also synthesized as a precursor to conjugated tropanyl enynes which would more closely resemble the natural product (1).
- Dharanipragada, Ramalinga,Fodor, Gabor
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p. 545 - 550
(2007/10/02)
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