- An unprecedented stereoselective base-induced trimerization of an α-bromovinylsulfone
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A unprecedented base-induced trimerization of bromovinylsulfone 1 afforded the cyclohexene 6 as a single diastereoisomer. Optimization of this reaction gave the adduct 6 in 49% yield. A mechanistic rationale for the trimerization involving consecutive SN2′ additions and [3,3]-rearrangements and a final stereoselective intramolecular conjugate addition is proposed and supported by M06-2X density functional theory calculations.
- Fisher, Brendan,Lepage, Romain J.,White, Jonathan M.,Ye, Young,Krenske, Elizabeth H.,Rizzacasa, Mark A.
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p. 5529 - 5534
(2017/07/12)
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- A one-pot regioselective synthetic route to vinyl sulfones from terminal epoxides in aqueous media
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A highly efficient LiBr catalysed regioselective synthesis of vinyl sulfones from readily available terminal epoxides and sodium sulfinates in a one-pot procedure using water as a reaction medium is reported. The protocol is adorned with several attributes of green chemistry like recycling of the catalyst, atom-economy and an aqueous medium.
- Chawla, Ruchi,Kapoor, Ritu,Singh, Atul K.,Yadav, Lal Dhar S.
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experimental part
p. 1308 - 1313
(2012/06/01)
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- 1-(N,N-diisopropylcarbamoyloxy)-1-tosyl-1-alkenes - a2d 1 synthons via tandem umpolung
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(Equation Presented) 1-(N,N-Diisopropylcarbamoyloxy)-1-tosyl-alkenes have been developed as an a2d1 synthon via tandem umpolung. Upon addition of Grignard reagents and further quench by carbonyl compounds, this synthon produces α,α′-
- Chen, Yue-Lei,Hoppe, Dieter
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supporting information; experimental part
p. 4188 - 4194
(2009/09/25)
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- Polystyrene-Supported α-Seleno Carbanions: Efficient Reagents for Highly Stereocontrolled Syntheses of Vinylphosphonates and Vinylsulfones
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Polystyrene-supported selenomethyl-phosphonate and polystyrene-supported selenomethyl-sulfonates have been prepared. These novel reagents were treated with LDA (or n-BuLi) to produce polystyrene-supported α-seleno carbanions, which reacted with alkyl halides, followed by stereospecific selenoxide syn-elimination to give E-vinylphosphonates and E-vinylsulfones respectively. And also these novel polymer reagents can be regenerated and reused.
- Xu, Wei Ming,Tang, E,Huang, Xian
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p. 2094 - 2098
(2007/10/03)
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- Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 12. Extrusion of Ph3P from sulfonyl ylides and reactivity of the resulting sulfonyl carbenes
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Twelve sulfonyl stabilised phosphorus ylides have been prepared and their behaviour upon flash vacuum pyrolysis at 600°C has been examined. Examples with an arylsulfonyl substituent undergo loss of Ph3PO to give intractable products but those with an arylmethylsulfonyl substituent separately lose Ph3P and SO2 to give products consistent with the intermediacy of sulfonyl carbenes. X-Ray structure determinations of one ylide from each series show a more significant P-O non-bonding interaction in the first case, providing some explanation for the different thermal reactivity.
- Aitken, R. Alan,Drysdale, Martin J.,Ferguson, George,Lough, Alan J.
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p. 875 - 880
(2007/10/03)
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- First synthesis, X-ray structure analysis and reactions of alkenyltriphenylbismuthonium salts
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Treatment of triphenylbismuth difluoride with alkenyltrimethylsilanes 1 or trimethylsilyl cyanidealkenyltrialkylstannanes 3 in the presence of boron trifluoride-diethyl ether gave the corresponding alkenyltriphenylbismuthonium tetrafluoroborates 2 in moderate to good yields. An X-ray crystallographic analysis of the salt 2e confirmed the distorted tetrahedral geometry of the central bismuth atom. When treated with a sulfinate 5 or the thiolate 11, the salts 2 readily transferred both the vinyl and phenyl moieties to these nucleophiles to afford the sulfones 7-10 or the sulfides 12, 13, respectively. In the presence of a palladium catalyst, the salt 2e underwent the Heck-type reaction with ethyl acrylate 17 to afford the dienoate 18 and cinnamate 19 in moderate yields. Action of KOBut on the salt 2b yielded p-tolylacetylene 22, while a similar reaction with the salt 2e in the presence of the styrenes 23 gave the cyclopropanes 24. A Hammett study of the latter reaction has suggested a possible involvement of an alkylidenecarbene as the intermediate in these base-promoted reactions.
- Matano, Yoshihiro,Yoshimune, Masanori,Azuma, Nagao,Suzuki, Hitomi
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p. 1971 - 1977
(2007/10/03)
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- Substitution Reactions of Organocuprates with β-(Phenylseleno)vinyl Sulfones Derived from the Selenosulfonation of Acetylenes. A Convenient and Stereospecific Preparation of Vinyl Sulfones and Olefins from Acetylenes
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The free-radical selenosulfonation of acetylenes affords β-selenovinyl sulfones 1 which undergo substitution of the selenium moiety with organocuprates to provide a convenient and stereospecific preparation of vinyl sulfones 2 and therefore ultimately of
- Back, Thomas G.,Collins, Scott,Krishna, M. Vijaya,Law, Kwok-Wai
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p. 4258 - 4264
(2007/10/02)
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- SELENOSULFONATION OF ACETYLENES. SUBSTITUTION REACTIONS OF β-(PHENYLSELENO)VINYL SULFONES WITH ORGANOCUPRATES
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β-(Phenylseleno)vinyl sulfones are readily available from the selenosulfonation of acetylenes and undergo efficient, stereoselective substitution of the phenylseleno moiety by the alkyl group of alkyl (phenylseleno)cuprates.
- Back, Thomas G.,Collins, Scott,Law, Kwok-Wai
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p. 1689 - 1692
(2007/10/02)
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- INVESTIGATION IN THE SERIES OF VINYLACETYLENE SULFONES. CYANATION REACTION
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Vinylacetylene sulfones ArSO2CH2CH=C(CH3)CCH react with acetone cyanohydrin in the presence of triethylamine to form unsaturated sulfonyl-substituted nitriles ArSO2CH2CH=C(CH3)CH=CH-CN.The vinylacetylene sulfide p-NO2C3H4SCH2CH=C(CH3)CCH does not en
- Bulat, A. D.,Antipov, M. A.,Belorusova, L. V.,Passet, B. V.
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p. 1923 - 1925
(2007/10/02)
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