- Gold-catalyzed intermolecular C-S bond formation: Efficient synthesis of α-substituted vinyl sulfones
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A general method for the synthesis of α-substituted vinyl sulfones makes use of a combination of a triazole gold complex and gallium triflate. This efficient C-S bond formation between simple terminal alkynes and sulfinic acids provides access to various α-substituted vinyl sulfones. Less basic, less hindered: The gold-catalyzed intermolecular Markovnikov addition of sulfinic acids to terminal alkynes has been achieved through the use of a bimetallic gold/gallium catalyst system. Various α-substituted vinyl sulfones were efficiently synthesized. A one-pot synthesis that starts from the bench-stable sodium sulfinates was also developed (DCE=1,2-dichloroethane).
- Xi, Yumeng,Dong, Boliang,McClain, Edward J.,Wang, Qiaoyi,Gregg, Tesia L.,Akhmedov, Novruz G.,Petersen, Jeffrey L.,Shi, Xiaodong
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supporting information
p. 4657 - 4661
(2014/05/20)
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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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- A General Synthetic Method for α-Methylene Compounds by the Palladium-Catalyzed Decarboxylation-Deacetoxylation of Allyl α-Acetoxymethylcarboxylates Substituted by an Electron-Withdrawing Group at α-Position
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Allyl α-acetoxymethylcarboxylates substituted by ester, amide, nitro, cyano, and sulfonyl groups at α-position undergo smooth palladium-catalyzed decarboxylation-deacetoxylation under mild neutral conditions to afford corresponding α-methylene compounds in high yields.
- Tsuji, Jiro,Nisar, Mohammad,Minami, Ichiro
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- A CONVENIENT METHOD FOR THE PREPARATION OF α-ALKYLATED VINYLIC SULFONES AND THEIR CONVERSION TO ALLYLIC SULFONES
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2-Pyrrolidinoalkyl p-tolyl sulfones, which were readily available by the addition of pyrrolidine to vinylic or allylic sulfones, were converted to the corresponding α-alkylated vinylic sulfones through α-alkylation followed by elimination of pyrrolidino g
- Inomata, Katsuhiko,Tanaka, Yuhji,Sasaoka, Shin-ichi,Kinoshita, Hideki,Kotake, Hiroshi
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p. 341 - 344
(2007/10/02)
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