- Enantioselective Oxidation of Thioethers: an Easy Route to Enantiopure C2 Symmetrical bis-Methylsulfinylbenzenes
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The direct oxidation of bis-methylthioethers 1 by t-butyl hydroperoxide, titanium tetra-isopropylate and (+)-diethyl tartrate, affords the almost enantiomerically pure dl bis-methylsulfinylbenzenes 2 (e.e. >/= 99percent) in a process which is also charact
- Bendazzoli, Paolo,Furia, Fulvio Di,Licini, Giulia,Modena, Giorgio
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- Synthesis and properties of novel medium-sized heterocyclic compounds containing two sulfur atoms in the ring and synthetic approaches to conjugated cyclic disulfonium ylides
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Tribenzo[bf,h][1,4]dithiecin (8) was prepared by coupling 2,2'- bis(bromomethyl)biphenyl (10) with 1,2-benzenedithiol (11) in the presence of Nail in acetonitrile. Another novel dithiecin derivative, 1,8-dihydro-2,7benzodithiecin (9) was synthesized by coupling of 1,4-dimercapto-2,3-Oisopropylidene-Lg-threitol (13a) with α,α'-dibromo-o-xylene (12), followed by hydrolysis and subsequent dehydration via the mesylate derivative (16). The benzodithiecin (9) was also prepared by treatment of dithiol (18) with butadiyne along with α,α'-bis(1-buten-3-ynylthio)-o-xylene (19) as a byproduct. Compound (19) was subjected to an intramolecular coupling reaction using CuCl-pyridine-O2 in benzene to yield the 12-membered ring compound (23). We also describe our effort to prepare the corresponding cyclic diylide compounds from the above new dithiecins (8) and (9), and known dithiecin (7).
- Shimizu, Hiroshi,Watanabe, Hiroyoshi,Mizuno, Masahiro,Kataoka, Tadashi,Hori, Mikio
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- ALTERNATIVE SYNTHESES OF DIBENZOTETRASELENAFULVALENE, OF SOME OF ITS PRECURSORS AND OF TETRASELENOALKENES ANALOGS
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We report alternative syntheses of dibenzotetraselenafulvalene, of a key precursor and of tetramethylselenoethylene.
- Lambert, Christian,Christiaens, Leon
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- t-BuOK-promoted methylthiolation of aryl fluorides with dimethyldisulfide under transition-metal-free and mild conditions
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In the presence of potassium tert-butoxide (t-BuOK), the cross-coupling reaction between aryl fluorides and dimethyldisulfide was developed. A series of aryl methyl sulfides were obtained in moderate to good yields under transition-metal-free and mild conditions.
- Huang, Dayun,Wu, Xiangmei
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- Meta -Non-flat substituents: A novel molecular design to improve aqueous solubility in small molecule drug discovery
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Aqueous solubility is a key requirement for small-molecule drug candidates. Here, we investigated the regioisomer-physicochemical property relationships of disubstituted benzenes. We found that meta-isomers bearing non-flat substituents tend to possess the lowest melting point and the highest thermodynamic aqueous solubility among the regioisomers. The examination of pharmaceutical compounds containing a disubstituted benzene moiety supported the idea that the introduction of a non-flat substituent at the meta position of a benzene substructure would be a promising approach for medicinal chemists aiming to improve the thermodynamic aqueous solubility of drug candidates, even though it might not be universally effective. This journal is
- Ichikawa, Yuki,Hiramatsu, Michiaki,Mita, Yusuke,Makishima, Makoto,Matsumoto, Yotaro,Masumoto, Yui,Muranaka, Atsuya,Uchiyama, Masanobu,Hashimoto, Yuichi,Ishikawa, Minoru
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supporting information
p. 446 - 456
(2021/01/29)
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- Reduction of CO2 with NaBH4/I2 for the Conversion of Thiophenols to Aryl Methyl Sulfides
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We report a tandem reaction to realize reduction of carbon dioxide with thiophenols to generate aryl methyl sulfides under the NaBH4/I2 system with 18-crown-6 as the solvent. Thiophenols bearing electron-donating and electron-withdrawing groups are feasible in this reaction. Controlled experiment results indicate that 18-crown-6 plays a critical role in six-electron reduction of carbon dioxide.
- Zhang, Bo,Fan, Zhengning,Guo, Zhiqiang,Xi, Chanjuan
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p. 8661 - 8667
(2019/07/03)
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- Metal-free radical thiolations mediated by very weak bases
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Aromatic thioethers and analogous heavier chalcogenides were prepared by reaction of arene-diazonium salts with disulfides in the presence of the cheap and weak base NaOAc. The mild and practical reaction conditions (equimolar reagents, DMSO, r.t., 8 h) tolerate various functional groups (e.g. Br, Cl, NO2, CO2R, OH, SCF3, furans). Mechanistic studies indicate the operation of a radical aromatic substitution mechanism via aryl, acetyloxyl, thiyl, and dimsyl radicals.
- Koziakov, Denis,Majek, Michal,Jacobi Von Wangelin, Axel
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supporting information
p. 11347 - 11352
(2016/12/16)
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- Oximesulfonic acid esters and the use thereof as latent sulfonic acids
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The invention relates to the use of oximesulfonic acid esters of formula I wherein m is 0 or 1 and x is 1 or 2; R1 is, for example, substituted phenyl, R2 has, for example, one of the meanings of R1 or is unsubstituted phe
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- Alkyl- and Arylthiodediazoniations of Dry Arenediazonium o-Benzenedisulfonimides. Efficient and Safe Modifications of the Stadler and Ziegler Reactions to Prepare Alkyl Aryl and Diaryl Sulfides
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The reaction between dry arenediazonium o-benzenedisulfonimides 1 and sodium thiolates in anhydrous methanol represents an efficient and safe procedure, of general validity, for the preparation of unfunctionalized or variously functionalized alkyl aryl and diaryl sulfides. As a rule, the reaction temperature was maintained at 0-5°C for the alkylthiodediazoniations and at room temperature (20-25°C) for the arylthiodediazoniations. The sulfide yields are generally high; of the 63 considered examples, 43 gave yields greater than 80% and 13 were between 70% and 80%. Lower yields were obtained only when sterically hindered diazonium salts or thiols were used. A good amount of the o-benzenedisulfonimide (8) was always recovered from the reactions and could be reused to prepare salts 1. The copious experimental data collected in homogeneous conditions have offered several starting points for the study of the mechanism of these reactions.
- Barbero, Margherita,Degani, Iacopo,Diulgheroff, Nicola,Dughera, Stefano,Fochi, Rita,Migliaccio, Mara
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p. 5600 - 5608
(2007/10/03)
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- ORGANOMETALLOIDAL COMPOUNDS WITH o-PHENYLENESUBSTITUENTS, PART XXVII. SYNTHESIS, CHARACTERIZATION AND STRUCTURE DETERMINATION OF 2,3,7,8-TETRAKIS(METHYLTHIO)- AND 2,3;7,8-BIS(ETHYLENEDITHIO)THIANTHRENE
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A generally applicable synthesis synthesis via the sequence thiophenol (3), 1,2-bis(alkylthio)benzene (6), 1-bromo-3,4-bis(alkylthio)benzene (7), bissulfide (8), bissulfide (9), 2,3,7,8-tetrakis(
- Doetze, M.,Klar, G.
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- ELEMENTORGANISCHE VERBINDUNGEN MIT o-PHENYLENSUBSTITUENTEN, XX. 2,3,7,8-TETRA(METHYLTHIO)THIANTHREN
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Starting from thiophenol (3) the sequence 1,2-di(methylthio)benzene (4) -> 1-bromo-3,4-di(methylthio)benzene (5) -> bissulfide (6) -> bissulfide (7) finally leads to the title compound 2.The 1H- and 13C-NMR, and the MS data of 2 are reported.The 1H-NMR data of compounds 5-7 are also given.
- Doetze, Marc,Klar, Guenter
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p. 217 - 222
(2007/10/02)
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- DIMETALLATION OF BENZENE
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Using the combination of n-butyllithium and soluble potassium t-alkoxides higher ratios of di- and mono-metallated benzene have been attained with n-butyllithium and the insoluble t-BuOK.
- Lochmann, L.,Fossatelli, M.,Brandsma, L.
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p. 529 - 530
(2007/10/02)
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- Regiochemistry and Stereochemistry of Nickel-Promoted, Carbon-Carbon Bond-Forming Reactions of Cyclic Sulfur Compounds
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Reaction of methylmagnesium iodide and phenylmagnesium bromide with thianaphthene, dibenzothiophenone, thianthrene, and 2,3-dihydrothiapyran in the presence of nickel dichloride have been shown to yield, regioselectively in most cases, ring-opened products in which the carbon-sulfur bonds have been replaced by carbon-carbon bonds.Stereospecific carbon-carbon bond formation has taken place in the reactions of thianaphthene and 2,3-dihydrothiapyran, the products having maintained the cis-olefin configuration of the starting sulfur compounds.Isomerization into the more stable compounds has been observed in some cases.
- Tiecco, Marcello,Tingoli, Marco,Wenkert, Ernest
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p. 3828 - 3831
(2007/10/02)
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- THE FACILE CONVERSION OF AROMATIC AMINES TO ARYLMETHYLSULFIDES WITH METHYLTHIOCOPPER
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Aromatic diazonium salts react readily with methylthiocopper, CuSCH3, to produce arylmethylsulfides in good yield.
- Baleja, James D.
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p. 215 - 218
(2007/10/02)
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- SYNTHESE NOUVELLE ET RAPIDE D'AKYLSELENO ET ALKYLTELLUROARENES AU MOYEN D'ETHERS-COURONNES
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A phase transfer catalytic synthesis of alkylseleno and alkyltelluroarenes is describe from arenediazonium tetrafluoroborates and dialkyldichalcogenides.
- Luxen, Andre,Christiaens, Leon
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p. 3905 - 3908
(2007/10/02)
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- Fragmentation of Aryl Alkyl Sulfides. A Simple, One-Pot Synthesis of Polymercaptobenzenes from Polychlorobenzenes
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A simple procedure is described which allows one to prepare polymercaptobenzenes starting from chlorobenzenes.The reactions of all the possible chlorobenzenes with Me2CHSNa in HMPA give the corresponding (isopropylthio)benzenes which can be cleaved by adding sodium to the reaction mixtures to give the arenethiolates in good yields.In some cases the polymercaptobenzenes were isolated after treatment with acid; in other cases methyl iodide was added to the reaction mixture and poly(methylthio)benzenes were obtained.It is suggested that the (isopropylthio)benzenes react with sodium to give the corresponding radical anions which fragment at the sulfur-alkyl bond to give the arenethiolates.
- Maiolo, Filippo,Testaferri, Lorenzo,Tiecco, Marcello,Tingoli, Marco
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p. 3070 - 3073
(2007/10/02)
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