- Aryl-substituted cyclopropyl acetylenes as sensitive mechanistic probes in the gold-catalyzed hydration of alkynes. comparison to the Ag(I)-, Hg(II)-, and Fe(III)-catalyzed processes
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The gold-catalyzed hydration of 2-phenyl- or 2,2-diphenylcyclopropyl acetylene, sensitive probes to trace the formation of vinyl carbocations, provides exclusively the corresponding cyclopropyl methyl ketones. On the other hand, in the Ag(I)- or Fe(III)-c
- Velegraki, Georgia,Stratakis, Manolis
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p. 8880 - 8884
(2013/09/24)
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- Stereoselective preparation of cyclopropylmagnesium reagents via a Br-Mg exchange using i-PrMgCl·LiCl in the presence of dioxane
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The reaction of various cyclopropyl bromides with i-PrMgCl·LiCl in THF-dioxane provides the corresponding magnesiated cyclopropane reagents with complete retention of configuration. Georg Thieme Verlag Stuttgart.
- Rauhut, Christian B.,Cervino, Christian,Krasovskiy, Arkady,Knochel, Paul
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scheme or table
p. 67 - 70
(2009/05/28)
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- The cyclopropyl group as a hypersensitive probe in the singlet oxygen ene reaction mechanism
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(Chemical Equation Presented) Cyclopropyl-substituted olefins are employed as mechanistic probes in the singlet oxygen-alkene ene reaction. In MeOH and aprotic solvents [CHCl3, (CH3)2CO, CH 3CN], only the allylic hydroperoxides bearing an intact cyclopropyl group are detected. The reaction mechanism is independent of solvent polarity. Our findings, to a certain experimental limit, exclude a biradical or dipolar intermediate.
- Alberti, Mariza N.,Orfanopoulos, Michael
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supporting information; experimental part
p. 2465 - 2468
(2009/05/27)
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- Copper-catalyzed electrosynthesis of 1-acyl-2,2-diphenylcyclopropanes and their behaviour in acidic medium
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The formation of 1-acyl-2,2-diphenylcyclopropanes is performed under mild electrochemical conditions. These cyclopropane derivatives, through acid-catalyzed ring-opening, lead to γ,γ-diphenyl-β,γ-unsaturated carbonyl compounds which evolve into either substituted naphthalenes, or β-benzhydryl-α,β-cycloalkenones depending on the acyclic or cyclic nature of the intermediate allyl ketone.
- Oudeyer, Sylvain,Léonel, Eric,Paugam, Jean Paul,Nédélec, Jean-Yves
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p. 1073 - 1081
(2007/10/03)
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- The tandem intermolecular Paterno-Buechi reaction: Formation of tetrahydrooxepins
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The Paterno-Buechi reaction is the [2 + 2] photocycloaddition between carbonyl compounds and electron rich alkenes to generate oxetane products. By the introduction of substituted cyclopropyl rings to the alkene components, the utility of this reaction has been extended to facilitate the synthesis of substituted tetrahydrooxepins. It is proposed that initial addition of oxygen radicals to cyclopropyl enol ethers generates cyclopropylmethyl radicals which, when the cyclopropane ring bears appropriate radical-stabilising groups (e.g. phenyl, CO2Et), undergo rapid fragmentation to form homoallylic 1,7-biradicals which then recombine to deliver the observed tetrahydrooxepin products. The importance of various radical-stabilising substituents on the efficiency of tetrahydrooxepin formation is examined.
- Gan, Chee Yong,Lambert, John N.
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p. 2363 - 2372
(2007/10/03)
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