- Preparation of Functionalized Acylsilanes by Diol Cleavage of Cyclic 1,2-Dihydroxysilanes
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We report a study on diol cleavage of cyclic 1,2-dihydroxysilanes for the preparation of functionalized acylsilanes. Sodium periodate turned out to be an efficient reagent for this transformation, resulting in good to excellent yields. The method is chara
- Zimdars, Patrick,B?hlig, Kristin,Metz, Peter
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p. 6163 - 6167
(2019/08/20)
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- Six- and five-membered 3-alkoxy-2-lithiocycloalkenes: New stable non-anionic β-functionalised organolithium compounds
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Naphthalene-catalysed reductive lithiation of various functionalised chlorocycloalkenes 18 leads to the corresponding non-anionic β-alkoxyfunctionalised organolithium reagents 14. Their reaction with different electrophiles, such as water, aldehydes, keto
- Yus, Miguel,Ramón, Diego J,Gómez, Inmaculada
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p. 5163 - 5172
(2007/10/03)
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- Preparation of amino substituted cyclic vinylsilanes by Wurtz-Fittig procedure
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The Wurtz-Fittig method of silylation of simple vinyl halides to vinylsilanes is extended to aminosubstituted vinyl halides. 2-Halo-3-morpholinylcycloalkenes can be silylated to the corresponding 2-trimethylsilyl-3-morpholinyl-1-cycloalkenes using excess of chlorotrimethylsilane and sodium in dioxane solvent without significant cleavage of C-N-morpholinyl bond under these metal reduction conditions. Similar success was not achieved with piperidinyl derivatives.
- HariPrasad,Nagendrappa, Gopalpur
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p. 1016 - 1019
(2007/10/03)
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- One-pot synthesis of α-trimethylsilyl enones from vinylsilanes
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Photooxygenation of vinylsilanes in the presence of acetic anhydride and pyridine afforded α-trimethylsilyl enones 1 in moderate to good yields. Since the required starting materials are readily available, the present approach constitutes a useful alterna
- Adam,Richter
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p. 176 - 180
(2007/10/02)
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- Generation and Solution-phase Behaviour of Some 2-Halogeno-1,3-ring-fused Cyclopropenes
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The title cyclopropenes 2b are readily formed by reaction of ring-fused β-silylated-gem-dihalogenocyclopropanes of the general type 1b with tetrabutylammonium fluoride in tetrahydrofuran solution.Those halogenocyclopropenes 2b which are fused to a seven-
- Banwell, Martin G.,Corbett, Madelaine,Gulbis, Jacqueline,Mackay, Maureen F.,Reum, Monica E.
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p. 945 - 964
(2007/10/02)
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- 1,3-Bridged Cyclopropenes
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Solid fluoride deposited on glass helices has been used to effect the gas-phase elimination of 1-(trimethylsilyl)-7-chlorobicyclo[4.1.0]heptane and 1-(trimethylsilyl)-8-chlorobicyclo[5.1.0]octane to yield bicyclo[4.1.0]hept-1(7)-ene and bicyclo[5.1.0]oct-1(8)-ene, respectively. Bicyclo[4.1.0]hept-1(7)-ene dimerizes below ca. -90 °C via an ene reaction to yield a new cyclopropene, which then couples to form tetramers. The structures of two tricyclohexane tetramers were determined by X-ray crystallography. The ene dimer was found to react with molecular oxygen to yield two carbonyl compounds identified as 2-(1-bicyclo[4.1.0]heptyl)cyclohexene-1-carboxaldehyde and 3-(1-bicyclo[4.1.0]heptyl)cyclohept-2-en-1-one. These compounds are thought to result from the reaction of molecular oxygen with carbenes that would arise from cyclopropene - vinylcarbene rearrangements. Bicyclo[5.1.0]oct-1(8)-ene is considerably more stable than its lower homologue but also dimerizes via an ene reaction 7-Chlorobicyclo[4.1.0]hept-1(7)-ene rearranges below -90 °C to yield 2-chloro-1,3-cycloheptadiene.
- Billups,Lee, Gon-Ann,Arney Jr., Benny E.,Whitmire, Kenton H.
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p. 7980 - 7984
(2007/10/02)
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- Palladium-mediated silylation of organic halides with disilane/F- reagent
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Under catalytic influence of tetrakis(triphenylphosphine)palladium, tris(diethylamino)sulfonium trimethyldiflourosilicate promoted the reaction of vynil halides with hexamethyldisilane to give corresponding vinyl silanes in good yields chemoselectivity and stereospecifically.
- Hatanaka, Yasou,Hiyama, Tamajiro
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p. 4715 - 4718
(2007/10/02)
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- Silanes in Organic Synthesis. 8. Preparation of Vinylsilanes from Ketones and Their Regiospecific Cyclopentenone Annulation
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A general method is described for the formation of vinylsilanes from ketones.Thus, conversion to the benzene- or p-toluenesulfonylhydrazone and sequential treatment with n-butyllithium and chlorotrimethylsilane in anhydrous tetramethylethylenediamine proceeds regiospecifically to afford the less substituted vinylsilane (in unsymmetrical cases).Friedel-Crafts acylation with acryloyl chlorides and aluminium chloride and subsequent Nazarov cyclization with Lewis acid catalysis results in cyclopentenone annulation.Numerous examples that reveal the scope of this processare described.Due to accompanying polymerization, annulation with acryloyl chloride itself is least efficient.This complication can, however, be averted through use of β-chloropropionyl chloride and dehydrochlorination with 1,5-diazabicycloundec-5-ene prior to ring closure.
- Paquette, Leo A.,Fristad, William E.,Dime, David S.,Bailey, Thomas R.
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p. 3017 - 3028
(2007/10/02)
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