- Aryl 1-chloroalkyl sulfoxides as acyl anion equivalents: A new synthesis of vinyl sulfides, ketones, and diketones from aryl 1-chloroalkyl sulfoxides and α,ω-dichloro-α,ω-disulfinylalkanes
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Treatment of aryl α-chloroalkyl sulfoxides, which were synthesized from aryl 1-chloroalkyl sulfoxides by alkylation with iodoalkanes, with trifluoroacetic anhydride and NaI in acetone at low temperature afforded vinyl sulfides in high yields. The vinyl sulfides were converted to ketones by hydrolysis with HClO4 in refluxing 1,4-dioxane in good yields. In this procedure, the lithiated aryl 1-chloroalkyl sulfoxides acted as acyl anion equivalents. The procedure was extended to a synthesis of α,ω-diketones starting from α,ω-dichloro-α,ω-disulfinylalkanes. The procedure was found to work well when the length of the carbon chain of the α,ω-disulfinylalkanes is longer than four, and the yields of the diketones were found to be somewhat variable (60-80%).
- Satoh, Tsuyoshi,Taguchi, Daisaku,Suzuki, Chihiro,Fujisawa, Satoshi
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p. 493 - 500
(2007/10/03)
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- A method for generation of α-halo carbanions (carbenoids) from aryl α-haloalkyl sulfoxides with alkylmetals
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Ligand exchange reaction of simple aryl α-haloalkyl sulfoxides with alkyllithium and ethylmagnesium halide at low temperature was investigated. On treatment of aryl α-haloalkyl sulfoxide with n-BuLi, t-BuLi, or EtMgX exclusively sulfur-alkyl bond-cleavage took place to afford α-halo carbanion (carbenoid). When this reaction was carried out without a proton source, the intermediate α-halo carbanion decomposed to give olefines in good yield. The ligand exchange reaction of sulfoxide was found to be very fast and the reaction could be carried out with a proton or a deuterium source (internal quench) to afford alkyl halide. This procedure offers a new method for preparing α-deuterated) halides (the halogen is F, Cl, or Br).
- Satoh, Tsuyoshi,Takano, Koji
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p. 2349 - 2358
(2007/10/03)
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