- Applications of surfactant-modified clays to synthetic organic chemistry
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Two triphase catalysts (SLL) have been developed for organic phase-aqueous phase reactions catalyzed by suitable modified clay (solid phase). These triphase catalysts have been applied to nucleophilic displacement on activated (benzylic) as well as unactivated organic halides and provide a convenient and effective method of preparation of the corresponding products. Other useful transformations to, which these triphase catalysts have been successfully applied are the synthesis of 9,9-dichloro bicyclo[6.1.0]nonane, O-alkylation and C-alkylation of β-naphthol.
- Ghiaci,Sedaghat,Kalbasi,Abbaspur
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p. 5529 - 5534
(2007/10/03)
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- Synthesis, characterization, and utility of trialkyl(3-sulfopropyl)ammonium betaines as new phase transfer reagents
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Synthesis of water-soluble phase transfer reagents, trialkyl(3-sulfopropyl)ammonium betaines and its utility in various hydroxide-ion initiated reactions are described.
- Jayachandran, Joseph Paul,Wang, Maw-Ling
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p. 2463 - 2468
(2007/10/03)
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- A new phase transfer reagent for the addition of dichlorocarbene to olefins under mild PTC conditions
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A three-step synthetic route to a novel water soluble phase transfer reagent, Diquat (Dq-Br), viz., 2-benzilidine-N,N,N,N',N',N'- hexaethyl propane-1,3 diammonium dibromide and its utility in various dichlorocarbenations to olefins are described.
- Jayachandran, J. Paul,Wang, Maw-Ling
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p. 4101 - 4112
(2007/10/03)
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- Photochemical activation of metalloporphyrin carbene complexes
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While the photochemistry of simple metalloporphyrin complexes has been explored to some extent, the photoactivation of multiple-bonded axial ligands coordinated to metalloporphyrins has not been previously examined. We report here the photochemistry of several iron porphyrin carbene and vinylidene complexes. Irradiation of these complexes with visible light cleaves the iron-carbon double bond and produces a four coordinate iron(II) porphyrin and a free carbene, which can be trapped in high yield with a variety of alkenes. This photochemistry is unique among organo transition metal complexes of carbenes or alkylidenes. For these metalloporphyrin carbene complexes, the presence of the porphyrin ring alters the photoreactivity of the metal-carbon bond. This is probably due to the mixing between the π * orbitals of the porphyrin ring and the iron-carbon orbitals, which is also responsible for the hypso-type spectrum (i.e. blue-shifted) seen in these complexes. Hypso spectra are a common trait in other photodissociative porphyrin complexes, most notably CO complexes.
- Ziegler, Christopher J.,Suslick, Kenneth S.
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- Carbon Tetrachloride-Dimethyl Sulphone-Potassium Hydroxide-t-Butyl Alcohol: a Convenient New Reagent for gem-Dichloromethylenation of Alkenes
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The action of dimethyl sulphone-potassium hydroxide-t-butyl alcohol on carbon tetrachloride readily affords dichlorocarbene.In the presence of alkenes, gem-dichlorocyclopropanes are formed in moderate to high yields.The dichlorocarbene generated by this procedure adds stereospecifically to alkenes with retention of geometric configuration about the carbon-carbon double bond.Relative reactivities of alkenes towards the CCl4-derived dichlorocarbene parallel the nucleophilicities of the alkenes and indicate that free dichlorocarbene is probably involved.
- Poon, Chi-Duen,Yuen, Po-Wai,Man, Tim-On,Li, Chun-Sing,Chan, Tze-Lock
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p. 1561 - 1563
(2007/10/02)
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- BICYCLOALKYLSILANES: NOUVELLE SYNTHESE ET REACTIVITE
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A new and competitive synthesis of bicyclotrimethylsilanes is reported, involving a facile and rapid process, and giving both endo and exo isomers.The behaviour of these species towrads acids (HCl, (AcOH)2BF3) has ben investigated.The stereochemist
- Ahra, M.,Grignon-Dubois, M.,Dunogues, J.
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- RELATIVE REACTIVITY OF CYCLOOLEFINS TOWARD DICHLOROCARBENES
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The relative rate constants for the addition of dichloro- and dibromocarbenes to cis- and trans-cycloalkenes, containing up to 12 carbon atoms in the ring, were determined.It was shown that the reaction is kinetically controlled and that the conformation of the ring exerts an important effect on the rate.
- Kostikov, R. R.,Molchanov, A. P.,Muehlstaedt, M.,Kuhl, P.
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p. 1062 - 1065
(2007/10/02)
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- GEM-DISILYLCYCLOPROPANES: PREPARATION ET UTILISATION EN SYNTHESE ORGANIQUE
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A simple general route for the conversion of olefins to gem-disilylcyclopropanes, involving the dichlorocyclopropanation of the double bond followed by silylation using the Me3SiCl/Li/THF reagent at 0-10 deg C, is described.Acetylation of bicyclic derivatives thus obtained constitutes an original synthesis of cycloalkylidene ketones by a process more convenient than those previously used, and also provides new acetyl dihydrofurans.
- Laguerre, Michel,Grignon-Dubois, Micheline,Dunogues, Jacques
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p. 1161 - 1169
(2007/10/02)
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