The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Kay Severin - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of trifluoromethyl-substituted cyclopropanes via sequential Kharasch-dehalogenation Reactions.
Organic Letters, 2012Co-Authors: Julie Risse, Mariano A. Fernandez‐zumel, Yanouk Cudre, Kay SeverinAbstract:A two-step process for the synthesis of trifluoromethyl-substituted cyclopropanes is described. Halothane, an anesthetic agent, is added to olefins in a ruthenium-catalyzed Kharasch Reaction. The resulting 1,3-dihalides are converted into cyclopropanes by dehalogenation with magnesium. This procedure represents an alternative to metal-catalyzed cyclopropanations involving trifluoromethyl diazomethane.
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Synthesis of Trifluoromethyl-Substituted Cyclopropanes via Sequential Kharasch–Dehalogenation Reactions
2012Co-Authors: Julie Risse, Mariano A. Fernández-zúmel, Yanouk Cudré, Kay SeverinAbstract:A two-step process for the synthesis of trifluoromethyl-substituted cyclopropanes is described. Halothane, an anesthetic agent, is added to olefins in a ruthenium-catalyzed Kharasch Reaction. The resulting 1,3-dihalides are converted into cyclopropanes by dehalogenation with magnesium. This procedure represents an alternative to metal-catalyzed cyclopropanations involving trifluoromethyl diazomethane
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Olefin Cyclopropanation by a Sequential Atom-Transfer Radical Addition and Dechlorination in the Presence of a Ruthenium Catalyst
Angewandte Chemie International Edition, 2009Co-Authors: Katrin Thommes, Gregor Kiefer, Rosario Scopelliti, Kay SeverinAbstract:Keywords: carbocycles ; cyclopropanes ; magnesium ; radicals ; ruthenium ; Gaba(C) Receptors ; Tert-Butyllithium ; Kharasch Reaction ; Copper-Complexes ; Reducing Agent ; Atrc Reactions ; Cyclization ; 1,3-Dihalopropanes ; Analogs ; Alpha,Omega-Dihaloalkanes Reference LCS-ARTICLE-2009-011doi:10.1002/anie.200904278View record in Web of Science Record created on 2009-09-28, modified on 2017-05-12
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Ruthenium Catalysts for the Kharasch Reaction
Current Organic Chemistry, 2006Co-Authors: Kay SeverinAbstract:Recent advances in the development of ruthenium catalysts for the atom transfer radical addn. of polyhalogenated compds. to olefins ('Kharasch Reaction') are described. Three classes of homogeneous catalysts are discussed: halfsandwich complexes with h6-arene, h5-cyclopentadienyl or h5-carborane ligands, ruthenium complexes with alkylidene- or vinylidene ligands and polynuclear complexes. Furthermore, first attempts to use immobilized ruthenium complexes as heterogeneous catalysts for the Kharasch Reaction are summarized.
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A Bimetallic Ruthenium Ethylene Complex as a Catalyst Precursor for the Kharasch Reaction
Organometallics, 2005Co-Authors: Laurent Quebatte, Rosario Scopelliti, Euro Solari, Kay SeverinAbstract:A bimetallic complex, in which a RuCl2 (eta(2)C(2)H(4))(PCy3) fragment is connected via three chloro, bridges to a (eta(6)-p-cymene)RuCl2 fragment, has been synthesized and characterized by single-crystal X-ray crystallography. This complex was used to catalyze the atom transfer radical addition Of CCl4 and CHCl3 to olefins at temperatures between 0 and 40 degrees C. Turnover frequencies of up to 1550 h(-1) were observed, making the new complex one of the most active catalysts for this type of Reaction described so far.
Julie Risse - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of trifluoromethyl-substituted cyclopropanes via sequential Kharasch-dehalogenation Reactions.
Organic Letters, 2012Co-Authors: Julie Risse, Mariano A. Fernandez‐zumel, Yanouk Cudre, Kay SeverinAbstract:A two-step process for the synthesis of trifluoromethyl-substituted cyclopropanes is described. Halothane, an anesthetic agent, is added to olefins in a ruthenium-catalyzed Kharasch Reaction. The resulting 1,3-dihalides are converted into cyclopropanes by dehalogenation with magnesium. This procedure represents an alternative to metal-catalyzed cyclopropanations involving trifluoromethyl diazomethane.
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Synthesis of Trifluoromethyl-Substituted Cyclopropanes via Sequential Kharasch–Dehalogenation Reactions
2012Co-Authors: Julie Risse, Mariano A. Fernández-zúmel, Yanouk Cudré, Kay SeverinAbstract:A two-step process for the synthesis of trifluoromethyl-substituted cyclopropanes is described. Halothane, an anesthetic agent, is added to olefins in a ruthenium-catalyzed Kharasch Reaction. The resulting 1,3-dihalides are converted into cyclopropanes by dehalogenation with magnesium. This procedure represents an alternative to metal-catalyzed cyclopropanations involving trifluoromethyl diazomethane
Yasuhiro Iwasawa - One of the best experts on this subject based on the ideXlab platform.
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immobilized metal ion containing ionic liquids preparation structure and catalytic performance in Kharasch addition Reaction
Chemical Communications, 2005Co-Authors: Takehiko Sasaki, Chongmin Zhong, Mizuki Tada, Yasuhiro IwasawaAbstract:Immobilized metal ion-containing ionic liquid catalysts were prepared by the Reaction between silyl-functionalized imidazolium ionic molecules and surface silanol groups of silica, followed by addition of MnCl2, FeCl2, CoCl2, NiCl2, CuCl2, or PdCl2; only the immobilized copper catalyst, which has a sandwiched CuCl42− moiety, was very active for the Kharasch Reaction between styrene and CCl4.
Michael G. Pamment - One of the best experts on this subject based on the ideXlab platform.
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The asymmetric Kharasch Reaction. Catalytic enantioselective allylic acyloxylation of olefins with chiral copper(I) complexes and tert-butyl perbenzoate
Tetrahedron Letters, 1995Co-Authors: M. B. Andrus, A. B. Argade, Xiao-ya Chen, Michael G. PammentAbstract:Olefins were treated with tert-butyl perbenzoate in the presence of hiral copper(I) triflate bisoxazoline complexes to give non-racemic allyl benzoates as products. The yields range from 34 to 62% and the enantiomeric excesses from 30 to 81%. A model for the selectivity is proposed.
Vinod K. Singh - One of the best experts on this subject based on the ideXlab platform.
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Asymmetric Kharasch Reaction: catalytic enantioselective allylic oxidation of olefins using chiral pyridine bis(diphenyloxazoline)-copper complexes and tert-butyl perbenzoate
The Journal of Organic Chemistry, 1998Co-Authors: Govindasamy Sekar, A. Dattagupta, Vinod K. SinghAbstract:Copper complexes of chiral pyridine bis(diphenyloxazoline)-type ligands have been studied as catalysts for the enantioselective allylic oxidation of olefins. Using 2.5−5 mol % of these chiral catalysts and tert-butyl perbenzoate as oxidant, optically active allylic benzoates were obtained in up to 86% ee. A variety of copper salts was studied under different conditions and in different solvents. Acetone was found to be a superior solvent for the Reaction. Use of phenylhydrazine in conjunction with the chiral copper complex played a crucial role in increasing the rate of the Reaction. Use of 4 A molecular sieves increased the optical yield of product in almost every case.
