- Synthesis of Acyl Alkenylindium Reagents and Their Application in the Synthesis of (Z)-α,β-Unsaturated Ketones via Palladium-Catalyzed Cross-Coupling Reaction
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A synthetic method for the preparation of acyl alkenylindium reagents was developed involving the hydroindation reaction of allenyl ketones with indium and indium chloride in methanol under mild conditions. Their synthetic applications were demonstrated from Pd-catalyzed cross-coupling reactions with aryl bromides and iodides and alkenyl and aryl triflates for the synthesis of (Z)-α,β-unsaturated ketones.
- Park, Youngchul,Min, Jiae,Eom, Dahan,Lee, Phil Ho
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p. 3934 - 3937
(2015/08/19)
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- 12-Te-5 Pertelluranes from 1,2-Oxatellurolyl-1-ium Halides. Synthesis, Structure, and Reactivity. The Quest for Delocalization in 10-Te-3 Telluranes and 12-Te-5 Pertelluranes of Thiathiophthene Structure
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The oxidative addition of chlorine or bromine to 1,2-oxatellurolyl-1-ium chlorides or bromides, respectively, at 0 deg C occurs rapidly to give 12-Te-5 pertelluranes.The structure of 3,5-diphenyl-1,2-oxatellurolylium tribromide (9) was determined unambiguously by single-crystal X-ray crystallographic analysis.Pertelluranes were neutral in solution (CH2Cl2), as determined by conductance studies.The pertelluranes were easily reduced electrochemically to halide ions and the oxatellurolylium halide and were susceptible to nucleophilic attack by Michael addition on the enone segment.Spectroscopic and crystallographic comparison of the pertelluranes with the corresponding oxatellurolylium halides and of dioxatellurapentalenes with the corresponding pertellurane analogues suggested ionic bonding between Te and the halides or O for all four of these systems.Theoretical treatment with CNDO/2 calculations by the program GEOMORV suggested ionic bonding of O and halides to the Te with little ?-delocalization involving Te-O and Te-C bonds in both the tellurane and pertellurane systems.A low-lying ?* LUMO in the pertelluranes was predicted, consistent with the susceptibility to nucleophilic attack, as observed experimentally.
- Detty, Michael R.,Luss, Henry R.,McKelvey, John M.,Geer, Susan M.
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p. 1692 - 1700
(2007/10/02)
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- The Compounds Related to 3-(1-Imidazolyl)-2-alken-1-ones. Preparation and Reactions
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Compounds related to 3-(1-imidazolyl)-2-alken-1-ones, 3-(1-imidazolyl)-2-alkenoic acid derivatives and 2-alken-1-ones having heterocycles on the C-3 carbon were prepared.The reaction of nucleophiles with these compounds was also discussed.
- Kashima, Choji,Tajima, Tadakuni,Omote, Yoshimori
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p. 171 - 176
(2007/10/02)
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- NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS. 46.1) TRIMETHYLSILYLDIAZOMETHANE: A CONVENIENT REAGENT FOR THE O-METHYLATION OF PHENOLS AND ENOLS
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Trimethylsilyldiazomethane reacts smoothly with phenols and enols in methanolic acetonitrile solution in the presence of N,N-diisopropylethylamine to give methyl ethers. KEYWORDS --- trimethylsilyldiazomethane; phenol; enol; O-methylation; methyl ether
- Aoyama, Toyohiko,Terasawa, Satomi,Sudo, Kimio,Shioiri, Takayuki
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p. 3759 - 3760
(2007/10/02)
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- The Reaction of 3-(1-Imidazolyl)-2-alken-1-ones with Nucleophiles
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Generally 3-hetero-substituted 2-alken-1-ones were prepared from 1,3-alkanediones, 3-chloro-2-alken-1-ones, or conjugated ynones.The preparation of 3-hetero-substituted 2-alken-1-ones was subjected to some limitations by these methods.By the reaction of 3-(1-imidazolyl)-2-alken-1-ones (I) and 3-(3-oxo-1-alkenyl)-1-methylimidazolium iodides (II) with nucleophiles, 3-hetero-substituted 2-alken-1-ones could be obtained regioselectively in good yield under mild conditions.These results suggested that compounds I and II were concluded to be useful intermediates for the organic synthesis.
- Kashima, C.,Tajima, T.,Shimizu, M.,Omote, Y.
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p. 1325 - 1328
(2007/10/02)
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- The Allopolarization Principle and its Applications, VI. The Alkylation of Enolate Anions: Polarity and Regioselectivity
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The O/C methylation ratio in the reaction of sodium enolates with dimethylsulfate depends on the polar (electronic) effect of substituents.The relative ?-charge density Px/y = lx/ly can be used as a measure for the polarity of ambifunctional anions; in case of enolate anions PO/C = lO/lC.The change of the regioselectivity Sf = log QO/QC in the alkylation of enolates is a function of a change in the polarity PO/C; ΔSf=f(ΔPx/y).The polar effect of substituents influences the charge control during the alkylation process via a change of the polarity of the enolate system: The higher the polarity of the anion, the stronger the charge control and the higher the yield of enol ether (O-alkylation). - Keywords: Alkylation, Enolate Anions
- Gompper, Rudolf,Vogt, Hans-Hubert,Wagner, Hans-Ulrich
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p. 1644 - 1652
(2007/10/02)
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