- Two-Step Synthesis of Furans by Mn(III)-Promoted Annulation of Enol Ethers
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Enol ethers, β-dicarbonyl compounds and the Mn(III) reagent Mn3O(OAc)7 react under mild conditions to form 1-alkoxy-1,2-dihydrofurans in good (70-98 percent) yields.The latter are readily converted to furans by acid catalyzed elimination of ROH.
- Corey, E. J.,Ghosh, Arun K.
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- Ruthenium Complexes Immobilized on Functionalized Knitted Hypercrosslinked Polymers as Efficient and Recyclable Catalysts for Organic Transformations
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A hypercrosslinked polymer (HCP)-immobilized ruthenium catalyst (HCP–PPh3–Ru) was prepared from benzene and triphenylphosphine (PPh3) through a one-step external cross-linking reaction. The structure and composition of the catalyst were fully characterized by many physicochemical methods. HCP–PPh3–Ru was found to possess high Brunauer–Emmett–Teller (BET) surface area, large pore volume, and low skeletal density. Moreover, the Ru catalyst was also featured some advantages, such as low synthetic cost and good chemical and thermal stability. HCP–PPh3–Ru was then used as a recoverable and effective catalyst for the synthesis of 2,4-diaryl-substituted pyridines from acetophenones, ammonium acetate (NH4OAc) and dimethylformamide (DMF), and the cycloaddition reaction of diazodicarbonyl compounds with olefins to afford dihydrofurans. In addition, a combination of HCP–PPh3–Ru and Amberlyst-15 enabled us to establish a simple protocol for the direct synthesis of carbazole derivatives from diazodicarbonyl compound, alkyl vinyl ether and indole. In these selected reactions, the catalyst was easily recovered and reused several times without significant activity loss. (Figure presented.).
- Jia, Zhifang,Wang, Kewei,Tan, Bien,Gu, Yanlong
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- One-pot Synthesis of Dihydrofuran Derivatives by Ru Catalyzed Reaction
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The present invention relates to a one-pot synthesis method of dihydrofuran derivatives using a ruthenium catalyst and, more particularly, to a one-pot synthesis method of dihydrofuran derivatives, which makes a reaction between cyclic/non-cyclic diazo dicarbonyl compound and olefin in the presence of ruthenium (II) phosphine complex as a reaction catalyst. The one-pot synthesis method of the present invention shortens time required for the reaction and improves synthesis yield. The diazo carbonyl compound represented by chemical formula 1, 2, or 3 reacts with olefin to form dihydrofuran derivatives through a [3+2] cyclization addition reaction.COPYRIGHT KIPO 2016
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Paragraph 0071; 0132; 0133; 0158; 0160; 0164-0167
(2016/10/10)
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- Efficient one-pot synthesis of multi-substituted dihydrofurans by ruthenium(II)-catalyzed [3+2] cycloaddition of cyclic or acyclic diazodicarbonyl compounds with olefins
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Ruthenium(II)-phosphine complexes-catalyzed [3+2] cycloadditions were conducted to synthesize a variety of dihydrofurans by reactions of cyclic or acyclic diazodicarbonyl compounds with olefins. This method represents a direct and efficient one-pot synthesis for multi-substituted dihydrofurans under mild reaction conditions with an excellent regioselectivity. Furthermore, to reduce reaction times and increase yields of dihydrofurans, microwave-as sisted tris(triphenylphosphine)ruthenium(II) chloride/ 1-butyl-3-methylimidazolium tetrafluoroborate {Ru (PPh3)3Cl2/ [Bmim]BF4}-catalyzed reactions were also developed. The synthesized dihydrofurans can be readily converted into biologically interesting tetrahydroindoles.
- Xia, Likai,Lee, Yong Rok
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p. 2361 - 2374
(2013/10/01)
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- INTERACTION OF ETHOXYACETALDEHYDE WITH 1,3-DICARBONYL COMPOUNDS
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It has been established that on interaction of ethoxyacetaldehyde with acetylacetone, acetoacetic ester, and benzoylacetone in the presence of piperidine acetate, β,γ-unsaturated compounds are formed, viz., 3-(2-ethoxy)vinyl substituted acetylacetone, ace
- Tanchuk, N. M.,Vartanyan, M. M.,Karzhavina, N. P.,Knyazhanskii, S. Ya.,Runova, E. A.,Karakhanov, E. A.
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p. 247 - 250
(2007/10/02)
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