- Improved generation method for functionalized nitrile oxide
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Gentle generation of nitrile oxide bearing a carbamoyl group was performed. 4-Nitro-3-isoxazolin-5-one was treated with dipolarophiles in the mixed solvent (MeCN/H2O) at room temperature to afford cycloadducts in good yields.
- Nishiwaki, Nagatoshi,Uehara, Toshiharu,Asaka, Noriko,Tohda, Yasuo,Ariga, Masahiro,Kanemasa, Shuji
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- 1,4-Diazabicyclo[2.2.2]octane (DABCO) as an efficient reagent for the synthesis of isoxazole derivatives from primary nitro compounds and dipolarophiles: The role of the base
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The dehydration of primary nitro compounds can be performed by bases in the presence of dipolarophiles. The reactivity of several tertiary amines or azaheteroaromatic compounds containing one or two basic centres is shown to be related to the ability of t
- Cecchi, Luca,De Sarlo, Francesco,Machetti, Fabrizio
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- Competitive Copper Catalysis in the Condensation of Primary Nitro Compounds with Terminal Alkynes: Synthesis of Isoxazoles
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Isoxazoles, mainly 3,5-disubstituted, are prepared by catalytic condensation of primary nitro compounds with terminal acetylenes by using a copper/base catalytic system. The additional catalytic effect of the copper(II) salts is evidenced by comparing the kinetic profiles. Selectivity dependence on reaction conditions is considered for phenylacetylene in the following competitive processes: oxidative coupling of terminal alkynes to conjugated diynes catalyzed by CuIIand base in the presence of air; production of furazans beside condensation with benzoylnitromethane to 3-benzoylisoxazoles, as a result of the reaction of the dipolarophile with 3,4-dibenzoylfuroxan; addition of electron-poor alkynes (e.g., methyl propiolate) with themselves and with the nitro compound. Thus, oxidative coupling is negligible in reactions with “active” nitro compounds, whereas with nitroalkanes both products are observed: only trace amounts of isoxazoles are detected without copper. Similarly, in the presence of copper, 3-benzoyl-5-phenylisoxazole is predominant over the furazan. Furthermore, condensations of electron-poor alkynes give complex reaction mixtures in the presence of base alone, but cycloadducts are conveniently prepared with copper. The results indicate the practical and general utility of this catalytic method for synthetic practice.
- Baglieri, Ausilia,Meschisi, Luca,De Sarlo, Francesco,Machetti, Fabrizio
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p. 4643 - 4655
(2016/09/28)
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- An anomalous hydration/dehydration sequence for the mild generation of a nitrile oxide
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A nitrile oxide containing a carbamoyl group is readily generated upon the treatment of 2-methyl-4-nitro-3-isoxazolin-5(2H)-one with water under mild reaction conditions, even in the absence of special reagents. The obtained nitrile oxide undergoes cycloa
- Nishiwaki, Nagatoshi,Kobiro, Kazuya,Kiyoto, Hideyuki,Hirao, Shotaro,Sawayama, Jun,Saigo, Kazuhiko,Okajima, Yoshikazu,Uehara, Toshiharu,Maki, Asaka,Ariga, Masahiro
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experimental part
p. 2832 - 2839
(2011/05/04)
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- Synthesis of 3-aminomethyl-substituted pyrazoles and isoxazoles
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A series of new 3-(aminomethyl)pyrazoles and 3-(aminomethyl)isoxazoles was synthesized along a route involving the formation as key intermediates of esters of 5-substituted 1H-pyrazole-3-carboxylic and 1H-isoxazole-3-carboxylic acids. All compounds obtain
- Musatov,Starodubtseva,Rakishev,Turova,Vinogradov
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experimental part
p. 1199 - 1203
(2011/12/15)
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- Synthesis and antimicrobial evaluation of new isoxazole carboxamides
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A new series of 5-phenyl-3-isoxazole carboxamides (4a-j) have been synthesized by reacting 5-phenyl-3-isoxazole carboxylate with various amines. All the synthesized compounds were characterized by their analytical and spectral data. These compounds were-e
- Lavanya,Narayan Reddy,Saritha Jyostna,Ramsubba Reddy
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p. 279 - 280
(2013/09/24)
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- Isoxazoles and isoxazolines by 1,3-dipolar cycloaddition: Base-catalysed condensation of primary nitro compounds with dipolarophiles
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1,4-Diazabicyclo[2.2.2]octane (DABCO) or other suitable N-bases cause primary activated nitro compounds to condense with alkenes to yield isoxazolines or with alkynes to give isoxazoles. As the molar ratio of the base with respect to the dipolarophile dec
- Machetti, Fabrizio,Cecchi, Luca,Trogu, Elena,De Sarlo, Francesco
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p. 4352 - 4359
(2008/04/13)
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- A NOVEL NITRILE OXIDE PRECURSOR; 2-METHYL-4-NITRO-5(2H)-ISOXAZOLONE
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2-Methyl-4-nitro-5(2H)-isoxazolone (1) was found to be a versatile precursor for a functionalized nitrile oxide by reaction with dipolarophiles giving 3-(N-methylcarbamoyl)isoxazole (2 or 3) derivatives.
- Higashida, Suguru,Nakashima, Hiroko,Tohda, Yasuo,Tani, Keita,Nishiwaki, Nagatoshi,Ariga, Masahiro
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p. 1511 - 1514
(2007/10/02)
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