51067-05-1Relevant articles and documents
Preparation method of 4, 5-dihydroisoxazole derivative
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Paragraph 0073-0139, (2021/02/13)
The invention discloses a preparation method of a 4, 5-dihydroisoxazole derivative, and relates to a prepartion method of a 4, 5-dihydroisoxazole derivative represented by formula (II). The method comprises the steps: reacting hydroxylamine hydrochloride
Efficient Synthesis of O - Tert -Propargylic Oximes via Nicholas Reaction
Nakamura, Itaru,Shiga, Keigo,Suzuki, Mao,Terada, Masahiro
, p. 3461 - 3465 (2020/08/10)
A synthetic protocol to access O - tert -propargylic oximes derived from tertiary propargylic alcohols was established via Nicholas reaction. Thus, BF 3·OEt 2-mediated reaction between the dicobalt hexacarbonyl complex of tert -propargylic alcohols and p -nitrobenzaldoxime followed by decomplexation with cerium(IV) ammonium nitrate afforded the corresponding O - tert -propargylic oximes in good to high yields. The obtained O - tert -propargylic oximes were effectively converted into heterocycles, such as four-membered cyclic nitrones, oxazepines, and isoxazolines, by using π-Lewis acidic catalysts.
Selectfluor-Bu4NI-Mediated C(sp3)-H Oxidation in Aqueous Media: Synthesis of Δ2-Isoxazolines from Oximes
Shi, Di,Qin, Hai-Tao,Zhu, Chen,Liu, Feng
supporting information, p. 5084 - 5088 (2015/08/18)
The direct functionalization of an aliphatic C-H bond within a complex molecule through a free-radical pathway is a valuable tool in synthetic chemistry. Herein, we developed an efficient transition-metal-free approach to generate Δ2-isoxazolines from oximes by radical-mediated C(sp3)-H oxidation. Investigation of the mechanism suggested that in the presence of Selectfluor and Bu4NI, the homolysis of the in situ formed O-I bond generated an iminoxyl radical that facilitated subsequent 1,5-H transfer and C(sp3)-H oxidation. The title reaction involves Selectfluor-Bu4NI-mediated C-O bond formation in aqueous media under metal-free conditions. A variety of Δ2-isoxazolines are directly synthesized from oximes by remote intramolecular functionalization of C(sp3)-H bonds.
Cobalt-catalyzed aerobic oxidative cyclization of β,γ- unsaturated oximes
Li, Weifei,Jia, Pingjing,Han, Bing,Li, Dianjun,Yu, Wei
, p. 3274 - 3280 (2013/04/24)
Cobalt complex Co(nmp)2 can efficiently catalyze the aerobic oxidative 5-exo cyclization of β,γ-unsaturated oximes to afford isoxazolines. The key cyclization step involves the generation of carbon-centred radicals. The products are largely dep
TEMPO-mediated aliphatic C-H Oxidation with Oximes and hydrazones
Zhu, Xu,Wang, Yi-Feng,Ren, Wei,Zhang, Feng-Lian,Chiba, Shunsuke
supporting information, p. 3214 - 3217 (2013/07/26)
A method for aliphatic C-H bond oxidation of oximes and hydrazones mediated by 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) has been developed, which enables the concise assembly of substituted isoxazole and pyrazole skeletons.
Aluminium triflate-catalysed regioselective cycloisomerisation of non-activated unsaturated oximes
Chaminade, Xavier,Chiba, Shunsuke,Narasaka, Koichi,Dunach, Elisabet
, p. 2384 - 2387 (2008/09/18)
A novel cycloisomerisation of oximes bearing non-activated C-C double bonds occurs in an Al(III)-catalysed reaction. This process leads to 5-, 6- and 7-membered ring oxygen and nitrogen-containing heterocycles in good yields.
Nitrosocarbonyl Intermediates as "Super-Enophiles": a Mild Method for Carbon-Nitrogen Bond Formation
Quadrelli, P.,Mella, M.,Caramella, P.
, p. 3232 - 3236 (2007/10/03)
Nitrosocarbonyl intermediates, generated at r.t. by the mild oxidation of nitrile oxides, undergo clean ene reactions with tetramethyl- and trimethyl-ethylene and with cyclohexene.With less substituted ethylenes the ene pathway is still active but the oxidation step of the nitrile oxides competes with the cycloadditions to the olefins. - Keywords: Cycloadditions; Ene reactions; Nitrile oxides; Nitroso compounds
