- A Facile Approach to the Synthesis of 3-Acylisoxazole Derivatives with Reusable Solid Acid Catalysts
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Nitrile oxides were formed from nitro ketones using silica gel-supported sodium hydrogen sulfate (NaHSO4/SiO2) or Amberlyst 15 as solid acid catalyst, and then the corresponding 3-acylisoxaszoles were obtained by reacting with alkynes via the 1,3-dipolar [3+2] cycloaddition. These heterogeneous catalysts are easily separable from the reaction mixture and reused. This synthetic method provides a facile, efficient, and reusable production of 3-acylisoxazoles.
- Itoh, Ken-Ichi,Hayakawa, Mamiko,Abe, Rina,Takahashi, Shinji,Hasegawa, Kenta,Aoyama, Tadashi
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supporting information
p. 4636 - 4643
(2021/09/20)
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- Iron-Mediated Synthesis of Isoxazoles from Alkynes: Using Iron(III) Nitrate as a Nitration and Cyclization Reagent
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A simple and direct method for the iron(III) nitrate-mediated synthesis of isoxazoles from alkynes has been developed; both self-coupling and cross-coupling products could be successfully prepared from alkynes. Meanwhile, for the cross-coupling and cyclizing of two different alkynes examined, the iron-mediated system shows a good chemoselectivity for the synthesis of corresponding isoxazoles. In our method, cheap and eco-friendly iron(III) nitrate is used as the nitration and cyclization reagent, and KI is used as the additive; they both play a positive role in this transformation. Furthermore, a different mechanism for the formation of isoxazoles from alkynes has been proposed.
- Lai, Zhenzhen,Li, Zhenxing,Liu, Yawei,Yang, Pengkun,Fang, Xiaomin,Zhang, Wenkai,Liu, Baoying,Chang, Haibo,Xu, Hao,Xu, Yuanqing
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p. 145 - 153
(2018/02/19)
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- Isoxazole compounds and synthetic method thereof
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The invention relates to a kind of isoxazole compounds and a synthetic method thereof. The structural formula of the compounds is shown in the specification, R1 is chlorophenyl, methylphenyl or acetylphenyl, R2 is hydrogen or methyl formate, and R3 is methyl formate, ethyl formate or phenoxymethyl. The substituted isoxazole compounds are a kind of important organic reaction intermediates, and can be used to conveniently rapidly synthesize a series of aromatic isoxazole derivatives through different types of organic chemical reactions, such as ring-opening reaction, addition reaction, substitution reaction and the like. The method raw materials are simple and easy to obtain. Cupric nitrate trihydrate is employed as a novel nitrogen source and oxygen source, and possesses best reaction activity under promotion effect of copper. Also, routine reaction solvents are employed, operation is simple, conditions are mild, the reaction is friendly to environment, the yield is medium to excellent, and extremely good development prospect in industrial production is provided.
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Paragraph 0020; 0021
(2016/10/08)
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- Application of silica gel-supported polyphosphoric acid (PPA/SiO 2) as a reusable solid acid catalyst to the synthesis of 3-benzoylisoxazoles and isoxazolines
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3-Benzoylisoxazoles were synthesized by the reaction of alkynes and benzoylnitromethane using silica gel-supported polyphosphoric acid (PPA/SiO 2). This reaction provides a convenient, efficient, and reusable synthetic method of isoxazole deriv
- Itoh, Ken-Ichi,Aoyama, Tadashi,Satoh, Hiroaki,Fujii, Yuki,Sakamaki, Hiroshi,Takido, Toshio,Kodomari, Mitsuo
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experimental part
p. 6892 - 6895
(2012/02/05)
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- Synthesis of pyrrolo[2,1-a]isoquinolines from activated acetylenes, benzoylnitromethanes, and isoquinoline
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Isoquinoline reacts smoothly with aroylnitromethanes in the presence of dialkyl acetylenedicarboxylates and dibenzoylacetylene to produce pyrrolo[2,1-a]isoquinolines in good yields. Quinoline and benzothiazole also react in a similar way. Pyridine and N-m
- Yavari, Issa,Piltan, Mohammad,Moradi, Loghman
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experimental part
p. 2067 - 2071
(2009/08/08)
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- REACTION OF PRIMARY NITRO COMPOUNDS WITH DIPOLAROPHILES IN THE PRESENCE OF p-TOLUENESULFONIC ACID.
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3-Substituted 2-isoxazolines or isoxazoles were obtained from the reaction of primary nitro compounds left bracket methyl nitroacetate, 2-nitro-1-phenylethanone, (nitromethyl)benzene, 1-nitropropane, and (phenylsulfonyl)-nitromethane right bracket with di
- Shimizu,Hayashi,Teramura
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p. 2531 - 2534
(2007/10/02)
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- SITE-SELECTIVITY OF 1,3-DIPOLAR CYCLOADDITIONS TO 2,3-DIMETHOXYCARBONYL-7-OXABICYCLO-HEPTADIENE
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Site-selectivity of dipolar cycloaddition to the title compound was studied.Azomethine X afforded a 1:1 cycloadduct XI at the deactivated double bond at room temperature;upon thermolysis at 110 degC it afforded the acetylated enamine XIII, wich was formed wia a direct cycloaddition at the mentioned temperature.The cycloaddition course was investigated in various solvents;the enamine XIV formed by solvolysis of XIII was the final products in methanol.Cycloaddition of title compound to azides, benzoylnitrile N-oxide and C-acetyl-N-phenylnitrilimine furnished the product of cycloreversion instead of the not isolable 1:1 cycloadducts.5-Azido-2-furancarbaldehyde and 4-nitrophenylazide yielded cycloaddition products to both multiple bonds in an approximately 1:1 ratio: HN3, tosylazide,benzoylnitrile N-oxide and C-acetyl-N-phenylnitrilimine gave the addition products to the deactivated double bond.The solvent-effect of site-selectivity of 1,3-dipolarcycloaddition was inwestigated and the title compound was found to be an exellent synthetic equivalent for acetylene and dimethyl butinedioate.
- Fisera, Lubor,Povazanec, Frantisek,Zalupsky, Peter,Kovac, Jaroslav,Pavlovic, Dusan
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p. 3144 - 3153
(2007/10/02)
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