- New approach to the synthesis of linear and cyclic vinyl(alkoxy)siloxanes
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Main products of the reaction of vinyltrichlorosilane VinSiCl3 with DMSO in the medium of tetra-(alkoxy)silane are linear siloxanes (RO)3Si[OSiVin(OR)]OSi(OR)3, RO[Vin(RO)SiO]nSi(OR)3 (R = Me, Et, n = 0–2) and the hitherto unknown cyclic siloxanes [Vin(RO)SiO]m[(RO)2SiO]4–m (m = 1–3) formed in the ratio of 70: 30%. A tentative scheme of their formation is suggested with participation of the products of the alkoxy groups exchange between vinyl(alkoxy)dichloro-, vinyldi(alkoxy)chloro-, trialkoxychloro-, and dialkoxydichlorosilanes.
- Basenko,Mailyan
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- A kinetics and mechanistic study of the atmospherically relevant reaction between molecular chlorine and dimethyl sulfide (DMS)
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A gas-phase kinetics study of the atmospherically important reaction between Cl2 and dimethyl sulfide (DMS) Cl2 + CH 3SCH3 → products (1) has been made using a flow-tube interfaced to a photoelectron spectrometer. The rate constant for this reaction has been measured at 1.6 and 3.0 torr at T = (294 ± 2) K as (3.4 ± 0.7) × 10-14 cm3 molecule-1 s -1. Reaction (1) has been found to proceed via an intermediate, (CH3)2SCl2, to give CH3SCH 2Cl and HCl as the products. The mechanism of this reaction and the structure of the intermediate were investigated using electronic structure calculations. A comparison of the mechanisms of the reactions between Cl atoms and DMS, and Cl2 and DMS has been made and the relevance of the results to atmospheric chemistry is discussed. The Owner Societies 2005.
- Dyke,Ghosh,Kinnison,Levita,Morris,Shallcross
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- Matrix Isolation Investigation of the Vibrational and Electronic Spectroscopy and Photochemistry of Complexes of ClF and Cl2 with Sulfide Bases
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Matrix isolation has been coupled with twin jet deposition for the formation of 1:1 molecular complexes of ClF and Cl2 with dimethyl sulfide and related bases.The infrared spectra of the complexes were dominated by an intense absorption which has been assigned to the perturbed halogen streching mode.This mode was greatly intensified and red-shifted upon complexes formation; the observed shifts of up to 300 cm-1 were much greater than shifts for the complexes of ClF with oxigen bases.The spectral differences have been rationalized in terms of hard/soft acid/base theory.Visible-ultraviolet spectra were also recorded for these complexes at high dilutions; for several an intense charge-transfer band was observed in the UV.Mercury arc irradiation into this charge-transfer absorption led to photochemically induced rearrangement reactions for several of complexes studied.
- Machara, Nicholas P.,Ault, Bruce S.
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- Complex of tetrachlorogermane with dimethyl sulfoxide and its IR spectral study
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The complex 2(Me2SO)_GeCl4 in which the hexacoordinate germanium atom is coordinated via oxygen atoms with two Me2S=O molecules was studied by IR spectroscopy. The strong doublet band with maxima at 495 and 506 cm-1/
- Voronkov,Gavrilova,Basenko
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- Reactions of alkali metal derivatives of metal carbonyls. VI. Some reactions of anions prepared from indenylmolybdenum tricarbonyl dimer and azulenedimolybdenum hexacarbonyl
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Indenylmolybdenum tricarbonyl dimer, [C9H7Mo(CO)3]2, is reduced by sodium amalgam in tetrahydrofuran to give a brown solution containing the [C9H7Mo(CO)2]- anion. This solution reacts with methyl iodide to form the expected yellow-orange tricarbonyl CH3Mo(CO)3C9H7. However, allyl chloride and chloromethyl methyl sulfide react with the [C9H7Mo(CO)3]- anion in tetrahydrofuran solution at room temperature to form the yellow dicarbonyls π-C3H5Mo(CO)2-C9H7 and π-CH3SCH2Mo(CO)2C9H7, respectively, in unusually facile decarbonylation reactions. Treatment of [C9H7Mo-(CO)3]2 with iodine in dichloromethane solution gives a brown dicarbonyl iodide C9H7Mo(CO)2I rather than the expected tricarbonyl iodide. Azulenedimolybdenum hexacarbonyl, C10H8Mo2(CO)6, reacts with sodium amalgam in tetrahydrofuran to give a yellow-brown solution which gives yellow dimeric [C10H8Mo(CO)3CH3]2 on treatment with methyl iodide.
- King,Bisnette
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- Aldehyde to Ketone Homologation Enabled by Improved Access to Thioalkyl Phosphonium Salts
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Phosphines were previously unusable as Pummerer-type nucleophiles due to competing redox chemistry with sulfoxides. Here we circumvent this problem to achieve a formal phosphine Pummerer reaction that offers thioalkyl phosphonium salts that, in turn, give rise to diverse vinyl sulfides via Wittig olefinations. Thirty vinyl sulfides are thus prepared from (alkylthioalkyl)triphenyl phosphonium salts and aldehydes. The hydrolysis of these vinyl sulfides offers an efficient and versatile two-step one-carbon homologation of aldehydes to ketones.
- Fragis, Meghan,Deobald, Jackson L.,Dharavath, Srinivas,Scott, Jeffrey,Magolan, Jakob
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supporting information
p. 4548 - 4552
(2021/06/28)
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- 4-AMINO OR 4-ALKOXY-SUBSTITUTED ARYL SULFONAMIDE COMPOUNDS WITH SELECTIVE ACTIVITY IN VOLTAGE-GATED SODIUM CHANNELS
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Disclosed are compounds of Formula (I), Formula (II), or a salt thereof: Formula (I) Formula (II) which compounds have properties for inhibiting Nav 1.7 ion channels found in peripheral and sympathetic neurons. Also described are pharmaceutical formulations comprising the compounds of Formula (I), Formula (II) or their salts, and methods of treating pain disorders, cough, and itch using the same.
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Page/Page column 56
(2020/07/05)
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- Consecutive C1-Homologation / Displacement Strategy for Converting Thiosulfonates into O,S-Oxothioacetals
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A conceptually intuitive synthesis of oxothioacetals is reported starting from thiosulfonates as electrophilic sulfur donors. The installation of a reactive CH2Cl motif with a homologating carbenoid reagent, followed by the immediate nucleophilic displacement with alcoholic groups [(hetero)-aromatic, aliphatic] offer a convenient access to the title compounds. Genuine chemoselectivity is uniformly observed in the case of multi-functionalized systems. (Figure presented.).
- Ielo, Laura,Pillari, Veronica,Miele, Margherita,Holzer, Wolfgang,Pace, Vittorio
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supporting information
p. 5444 - 5449
(2020/10/12)
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- DMSO as a Switchable Alkylating Agent in Heteroarene C?H Functionalization
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Herein, we report a novel strategy for the activation of DMSO to act as a versatile alkylating agent in heteroarene C?H functionalization. This direct, simple, and mild switch between methylation/trideuteromethylation and methylthiomethylation of heteroarenes was achieved under reagent-controlled photoredox catalysis conditions. The proposed mechanism is supported by both experimental and computational studies.
- Garza-Sanchez, R. Aleyda,Patra, Tuhin,Tlahuext-Aca, Adrian,Strieth-Kalthoff, Felix,Glorius, Frank
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supporting information
p. 10064 - 10068
(2018/07/29)
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- Acylation mechanisms of DMSO/[D6]DMSO with Di-tert-butylketene and its congeners
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Dimethyl sulfoxide (DMSO) and tBu2C=C=O in diglyme require heating to about 150 °C to furnish the Pummerer-type product tBu 2CHCO2CH2SCH3 through a novel mechanistic variant. The "ester enolate" tBu2C=C(O -)-O-S+(CH3)2 arising through the reversible addition of DMSO (step 1) to C-1 of tBu2C=C=O must be trapped through protonation (step 2) at C-2 by a carboxylic acid catalyst to form tBu2CH-C(=O)-O-S+(CH3)2 so that the reaction can proceed. The ensuing cleavage (step 3) of the O-S bond and one of the C-H bonds in the-S(CH3)2 group (E2 elimination, no ylide intermediate) results in the formation of tBu2CHCO 2- and H3CS-CH2+, whose combination (step 4) generates the final product. With a mixture of DMSO and [D6]DMSO competing for tBu2C=C=O in diglyme, the small value of the kinetic H/D isotope effect (KIE) kH/kD = 1.26 at 150 °C indicates that the cleavage of the C-H/C-D bonds (step 3) does not occur in the transition state with the highest free enthalpy. Therefore, the practically isotope-independent steps 1 and 2 determine the overall rate. The alternative slow initial protonation at C-2 of tBu2C=C=O generating the acylium cation tBu2CHC≡O+ can be excluded. Preparatory studies were undertaken to compare the mechanistic behavior of tBu2C=C=O with that of two related acylating agents: (i) The anhydride (tBu2CHCO)2O affords the same Pummerer-type product more slowly, again with an unexpectedly small KIE of 1.24 at 150 °C, which indicates that the overall rate is limited here by the almost isotope-independent initial O-acylation of DMSO in the addition/elimination (AE) mechanism. (ii) The acyl chloride tBu2CHCOCl affords ClCH 2SCH3 through a more common mechanistic variant involving neither the ketene nor the acylium cation tBu2CHC≡O +: The modestly enhanced kH/kD value of 2.4 at 55 °C shows that the C-H/C-D bond fissions contribute to the overall rate in cooperation with the retarded initial O-acylation. Deuterium labeling was quantified through 1H and 13C NMR integrations of deuterium-shifted signals.
- Knorr, Rudolf
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scheme or table
p. 6335 - 6342
(2011/12/05)
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- Reaction of organylchlorosilanes with dimethyl sulfoxide in the presence of octamethyltrisiloxane
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Dichloro(methyl)(vinyl)silane reacts with DMSO in the presence of octamethyltrisiloxane to form cyclooligomethyl(vinyl)siloxanes(MeViSiO) n (n = 3-6). The reaction involves disproportionation of octamethyltrisiloxane into hexamethyldisiloxane and decamethyltetrasiloxane. Along with the latter two products, insertion products of methyl vinyl silanone into both permethyloligosiloxanes were identified. Alkyltrichlorosilanes RSiCl3 (R = Me, Et) react with DMSO in the presence of octamethyltrisiloxane to form cyclic oligoalkyltrichlorosiloxanes (RClSiO) m (m = 3-6).
- Basenko,Gebel',Boyarkina,Voronkov
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p. 882 - 884
(2007/10/03)
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- Isothiazolecarboxylic acid derivatives and their use as microbicides
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Novel isothiazolecarboxylic acid derivatives of the formula (I), in which A, Q, Z and k have the meanings mentioned in the specification, processes for the preparation of the new compounds and their use as microbicides.
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- Generation and capture of alkylchlorosilanones
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Alkyltrichlorosilanes react with DMSO (molar ratio 1 : 1, 0 °C) to give cyclic oligoalkylchlorosiloxanes of the general formula [R(Cl)SiO]n (where R = Me or Et; n = 3-6). With an excess of alkyltrichlorosilane (2 : 1), linear oligoalkylchlorosiloxanes Cl[R(Cl)SiO]mSiCl2R (where R = Me or Et; m = 1-5) are also formed. In the presence of hexamethyldisiloxane (molar ratio Cl3SiR : DMSO : (Me3Si)2O = 1 : 1 : 2, 20 °C), the reaction products are both cyclic and linear oligoalkyl(trimethylsilyloxy)siloxanes [R(Me3SiO)SiO]n (n = 3-5) and Me3Si[OSi(OSiMe3)R]mOSiMe3 (m = 1-3), respectively. The reaction of DMSO with trichloro(vinyl)silane and hexamethyldisiloxane occurs in a similar manner. A plausible scheme of formation of the final products via intermediate alkylchlorosilanones RClSi=O and alkyl(trimethylsilyloxy)silanones is discussed.
- Basenko,Voronkov,Gebel
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p. 363 - 366
(2007/10/03)
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- Generation and capture of methyl(vinyl)silanone
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Methyl(vinyl)dichlorosilane reacts with DMSO in the presence of hexamethyldisiloxane to give the corresponding linear oligosiloxanes of the general formula Me3Si(OSiMeVin)nOSiMe3 (n = 1-6) as well as MeSi(OSiMe3)3 and Me3Si(MeOSiVin)mOSi(OSiMe3)(Me)OSiMe 3 (m = 1-2). The same reaction in the presence of chlorotrimethylsilane results in oligomers of the general formula Me3Si(OSiMeVin)nCl (n = 1-3). A possible scheme of their formation is discussed.
- Basenko,Gebel,Voronkov,Klyba,Mirskov
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p. 1571 - 1573
(2007/10/03)
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- Ozonides of Acyclic Olefins Having Mono- and Dichloro-Substituted Double Bonds
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Ozonolyses of acyclic olefins containing 1,2-dichloro-substituted (4a,b) and monochloro-substituted double bonds (7a, b, 12) as well as two (4a, b, 7a, b) or one halomethyl group (12) attached to the double bond afford the corresponding ozonides as the first representatives of monocyclic chlorinated ozonides.Their stability decreases in order 5a, 5b > 8a, 8b > 13. - Key Words: Ozonides/ 1,2,4-Trioxolanes, 3-chloro-, 3,5-dichloro- / Polyethylene
- Griesbaum, Karl,Schlindwein, Konrad,Hilss, Michael
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p. 1843 - 1848
(2007/10/02)
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- Photoisomerization of Halogendimethyl Sulfides
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Photolysis of iodo- (3a), bromo- (3b), and chlorodimethyl sulfide (3c) in an argon matrix at 12 K gives rise to isomeric species 4a-c.Ab initio calculations indicate that in these isomers the halogen has been removed from the carbon atom and forms a weak bond to the sulfur atom.The conclusion is based on the comparison of observed and calculated IR spectra of the photoisomers. Key Words: Matrix isolation / Halogen shift / Calculations, ab initio / Photochemistry
- Maier, Guenther,Floegel, Ulrich,Reisenauer, Hans Peter,Hess, B. Andes,Schaad, Lawrence J.
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p. 2603 - 2608
(2007/10/02)
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- Cephalosporin derivatives
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This is a class of antibacterial compounds of the formula: STR1 wherein Y is straight or branched alkyl or alkenyl chain, cycloalkanomethyl of 3-6 carbon atoms, each group being optionally substituted by halogen, or a group STR2 wherein n is 0 or an integer of 1-3, A is a group --COR3 wherein R3 is hydroxy, a group STR3 wherein R4 and R5, which may be the same or different, are hydrogen or alkyl of 1-5 carbon atoms, a group STR4 or a 5- or 6-membered heterocyclic group containing nitrogen and/or sulfur, and R1 and R2, which may be the same or different, are hydrogen, alkyl of 1-5 carbon atoms, or R1 and R2 may be combined together to form cycloalkylidene of 3-5 carbon atoms, and Z is a group of the formula: STR5 wherein m is 0 or an integer of 3-5, R6 is hydrogen or alkyl of 1-3 carbon atoms, and R7, when m is an integer of 3-5, is alkyl of 1-5 carbon atoms, alkenyl, cyclopropyl, a group --(CH2)p B wherein p is 0 or an integer of 1-3 and B is amino, alkyl-substituted amino, hydroxy, carboxy, carbamoyl, trifluoromethyl, sulfonic acid, sulfonic acid amide, alkylthio or cyano or, when m is 0, is alkyl of 1-5 carbon atoms, which may optionally be substituted by halogen, alkenyl, a group STR6 wherein R8 is hydrogen, alkyl of 1-4 carbon atoms or phenyl, or cyclopropyl, and a salt thereof.
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- Regiochemistry and reactivity in the chlorination of sulfides
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Huheey's original method for the calculation of substituent electronegativities is modified so that isomeric groups have different electronegativities.The modified form of Huheey's method is then employed to show that our previously published method for anticipating regiochemistry in asymmetric sulfide chlorination, i.e., ΔXP calculations for the α and α' substituents in the sulfide substrates, is successful in all fifty known cases.A new reactivity function (RP) is defined, for the sulfenium ion intermediates, which permits one to anticipate when substrates become inert to chlorine in exhaustive chlorinations conducted in aprotic media.
- Hancock, James Reid,Hardstaff, William Rayne,Johns, Paul Alan,Langler, Richard Francis,Mantle, William Stanley
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p. 1472 - 1480
(2007/10/02)
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- PREPARATION AND REACTIONS OF trans- (R = Me, Ph or C6H4Me-p)
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Formation of trans- (R=Me, Ph or C6H4Me-p) has been achieved by the oxidative addition of ClCH2SR to (PPh3)4Pt in refluxing PhH.The reaction of ClCH2SMe with (PMe2Ph)4Pt led to cis-.The reaction of trans-(PPh3)2Pt(CH2S
- McPherson, Helen,Wardell, James L.
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p. 261 - 266
(2007/10/02)
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- DIMETHYLSULPHOXIDE ADDUCTS WITH CHLORINATED LEWIS ACIDS AND WITH CHLORINE: NMR INVESTIGATIONS
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The structure and mechanism of formation of the ionic species formed in the reaction of dimethylsulfoxide with COCl2, POCl3, PCl5, Cl2CHOCH3, (CH3)2N=CHCl(1+), Cl(1-) or OPOCl(2-), and Cl2 are studied by proton, carbon and phosphorus NMR.
- Gouvreau, J. R.,Poignant, S.,Martin, G. J.
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p. 1319 - 1322
(2007/10/02)
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