1918-82-7Relevant articles and documents
OXIDATIVE DEHYDROGENATION OF ALKYLHETEROAROMATIC COMPOUNDS. 2. DEHYDROGENATION OF ALKYLTHIOPHENES
Belomestnykh, I.P.,Rozhdestvenskaya, N.N.,Isagulyants, G.V.
, p. 888 - 891 (1994)
The dehydrogenation of a series of alkylthiophenes has been studied on vanadium-magnesium systems in the presence of atmospheric oxygen, and zinc-chromium oxide catalysts in the absence of oxygen.Optimum conditions heve been determined for bringing this about enabling vinylthiophenes to be obtained in high yield and with high selectivity.The advantages of the oxidative dehydrogenation method have been shown in the synthesis of vinyl derivatives of thiophene.
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Emerson,Patrick
, p. 729,732 (1948)
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Stereoselective Gold(I)-Catalyzed Vinylcyclopropanation via Generation of a Sulfur-Substituted Vinyl Carbene Equivalent
Yuan, Tengrui,Ryckaert, Bram,Van Hecke, Kristof,Hullaert, Jan,Winne, Johan M.
, p. 4070 - 4074 (2021)
A stereoselective gold(I)-catalyzed vinylcyclopropanation of alkenes has been developed. A gold-coordinated cationic vinyl carbene species, readily generated via a rearrangement of the ethylenedithioacetal of propargyl aldehyde, reacts with a wide range of alkenes to afford thio-substituted vinylcyclopropanes. The gold-catalyzed vinyl cyclopropanation proceeds under mild conditions at room temperature and is generally selective for the formation of cis-substituted cyclopropanes. The reaction allows the formal introduction of a “naked” vinyl carbene, by subsequent chemoselective hydrodesulfurisation of the ethylenedithio-bridge. The synthetic utility of the new method is demonstrated by a short, racemic formal synthesis of the alkaloid cephalotaxin, hinging on a key vinyl cyclopropane-cyclopentene rearrangement.
Iron-Catalyzed Direct Julia-Type Olefination of Alcohols
Landge, Vinod G.,Babu, Reshma,Yadav, Vinita,Subaramanian, Murugan,Gupta, Virendrakumar,Balaraman, Ekambaram
, p. 9876 - 9886 (2020/09/03)
Herein, we report an iron-catalyzed, convenient, and expedient strategy for the synthesis of styrene and naphthalene derivatives with the liberation of dihydrogen. The use of a catalyst derived from an earth-abundant metal provides a sustainable strategy to olefins. This method exhibits wide substrate scope (primary and secondary alcohols) functional group tolerance (amino, nitro, halo, alkoxy, thiomethoxy, and S- A nd N-heterocyclic compounds) that can be scaled up. The unprecedented synthesis of 1-methyl naphthalenes proceeds via tandem methenylation/double dehydrogenation. Mechanistic study shows that the cleavage of the C-H bond of alcohol is the rate-determining step.
Br?nsted Acid Catalyzed Peterson Olefinations
Britten, Thomas K.,McLaughlin, Mark G.
, p. 301 - 305 (2019/12/25)
A mild and facile Peterson olefination has been developed employing low catalyst loading of the Br?nsted acid HNTf2. The reactions are typically performed at room temperature, with the reaction tolerant to a range of useful functionalities. Furthermore, we have extended this methodology to the synthesis of enynes.