- Method for synthesizing methyl heptenone from methyl butynol
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The invention provides a method for synthesizing methyl heptenone from methyl butynolwhich. The method comprises the following steps: carrying out a rearrangement reaction on methyl butynol and 2-alkoxy propylene under the action of an acid catalyst to obtain a mixture of allenyl ketone and methylheptadienone; and carrying out selective hydrogenation on the mixture under the action of a hydrogenation catalyst to obtain the methyl heptenone product. The synthesis route is novel, firstly, the rearrangement reaction is firstly carried out to obtain allenyl ketone and methylheptadienone intermediates, and the problem of low selectivity of enol synthesis by alkynol hydrogenation is avoided; sulfonic acid resin and a Lewis acid are used for a synergistic catalytic reaction, so that the rearrangement reaction condition is mild; then hydrogenation of allenyl ketone and methylheptadienone is catalyzed by using a Lindelar catalyst and taking an alkali and quinoline as assistants so as to obtainthe methyl heptenone with high selectivity; and the method has the advantages of readily available starting raw materials, low price, high total yield of the route, good cost advantage and potential application prospect.
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Page/Page column 5-11
(2020/05/02)
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- Method for synthesizing alpha,gamma-unsaturated dienone from propargyl alcohol and catalyst system used for method
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The invention discloses a method for synthesizing alpha,gamma-unsaturated dienone from propargyl alcohol and a catalyst system used for the method. The method comprises the following steps: (1) a Saucy-Marbet reaction is carried out on propargyl alcohol and alkoxy propylene under the action of an acidic resin catalyst to obtain an allenyl ketone intermediate; and (2) a heterogeneous reaction is carried out on the allenyl ketone under the action of a solid base catalyst to obtain the alpha,gamma-unsaturated dienone product. The method disclosed by the invention has the main advantages that solid catalysts are adopted in the two steps of reactions, the catalyst activity is high, and the catalysts are easy to separate from products. Compared with a separation process in an existing homogeneous acid catalysis process, the separation process in the method provided by the invention is greatly simplified. Secondly, the acid resin catalyst and solid base catalyst adopted in the method both canbe continuously recycled, so that the cost is low, and the method is economical and feasible and is superior to the existing known process.
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- Palladium-Catalyzed Cleavage of α-Allenylic Aryl Ether toward Pyrazolemethylene-Substituted Phosphinyl Allenes and Their Transformations via Alkenyl C-P(O) Cleavage
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A palladium-catalyzed two-component coupling of allenylphosphine oxides with conjugated N-tosylhydrazones is revealed. For the first time, the cleavage of α-allenylic aryl ether toward pyrazolemethylene-substituted phosphinyl allenes enabled facile synthesis of combined motifs with pyrazole and allene. Moreover, the obtained adducts could be easily transformed to potential bioactive multifunctionalized phosphinates via a novel alkenyl C-P(O) cleavage.
- Zhu, Jie,Mao, Mao,Ji, Huan-Jing,Xu, Jiang-Yan,Wu, Lei
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supporting information
p. 1946 - 1949
(2017/04/28)
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- Gold-catalyzed cycloisomerization of cyclopropyl alkynyl acetates: A versatile approach to 5-, 6-, and 7-membered carbocycles
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Nonclassical chirality transfer? Depending on the substitution pattern of propargyl acetates, a gold-catalyzed homologous Rautenstrauch reaction generates either 5- or 6-membered ring systems (see scheme). The stabilization of cationic intermediates is crucial for this reaction to succeed. The underlying principle for the good chirality transfer observed could be gold-stabilized nonclassical carbocations having configurational stability.
- Zou, Yue,Garayalde, David,Wang, Quanrui,Nevado, Cristina,Goeke, Andreas,Ito, Yoshihiko
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supporting information; experimental part
p. 10110 - 10113
(2009/05/30)
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- New Insights on the Reaction of Alkyl 3-Oxo-4-(triphenylphosphoranylidene)butanoate and Aldehydes under Concentrated Condensation Conditions. One-Pot Synthesis of Highly functionalised 6-Oxocyclohex-4-ene-1,3-dicarboxylates
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New annulation methodologies for the construction of substituted cyclohex-2-enones are important in organic synthesis. In this paper wee describe a new one-pot synthesis of substituted cyclohexenonedicarboxylates in maximum yield of 52 percent from the condensation of alkyl 3-oxo-4-(triphenylphosphoranylidene)-butanoate 1 and aldehydes.
- Moorhoff, Cornelis M.,Schneider, David F.,Winkler, Dave
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p. 3461 - 3483
(2007/10/03)
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- SOME FEATURES OF THE REARRANGEMENT OF TERTIARY ETHYNYLCARBINOLS IN THE PRESENCE OF POLYVANADIOORGANOSILOXANES
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The rearrangement of various tertiary ethynylcarbinols to α,β-unsaturated aldehydes, catalyzed by polyvanadioorganosiloxanes, was studied, and the activation parameters of the reaction were determined.The structures of the side products were established, and proposals were made about the mechanism of their formation.Additives which suppress the side reactions were found.As a result the yields of the unsaturated aldehydes were increased significantly.
- Erman, M. B.,Aul'chenko, I. S.,Kheifits, L. A.
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