- Nitrile oxide 1,3-dipolar cycloaddition by dehydration of nitromethane derivatives under continuous flow conditions
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Aliphatic nitrile oxides were generated in situ, by dehydration of terminal nitro compounds, and reacted with dipolarophiles using continuous flow techniques to afford substituted isoxazolines. The yields of cycloadducts were comparable with traditional f
- Brasholz, Malte,Saubern, Simon,Savage, G. Paul
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experimental part
p. 1397 - 1401
(2012/02/01)
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- Magtrieve (CrO2) and MnO2 mediated oxidation of aldoximes: Studying the reaction course
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Magtrieve (CrO2) and MnO2 mediated oxidation of aldoximes to nitrile oxides were studied in details. In presence of external radical source, TEMPO, these reagents did not furnish nitrile oxides, instead favoured deoximation to aldehydes. A common trend of deoximation was established from electronically tuned aldoximes, which is: aliphatic>aromatic> aldoximes with strong electron-withdrawing group, though the extent of deoximation was less in case of CrO2. Above effects were not observed with chloramine-T and diacetoxyiodobenzene, reagents known to produce nitrile oxides via hydroximoyl halide or equivalent ionic intermediates. A putative reaction mechanism is proposed for MO2 (M=Cr, Mn) mediated oxidation of aldoximes through formation of a nitroso-oxime tautomeric pair. Formation of nitrile oxide is possibly occurred from the oxime tautomer via a σ-type iminoxy radical intermediate. The deoximation process, dominating in presence of external radical environment, is explained following decomposition of the nitroso tautomer.
- Bhosale, Sandeep,Kurhade, Santosh,Vyas, Samir,Palle, Venkata P.,Bhuniya, Debnath
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scheme or table
p. 9582 - 9588
(2011/01/03)
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- An expeditious synthesis of isoxazoline using cetyltrimethylammonium cerium nitrate: A phase transferring oxidative 1,3-dipolar cycloaddition
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An expeditious and effective method for synthesis of isoxazoline from aldoximes and activated alkenes using cetyltrimethylammonium cerium nitrate at room temperature is described. Reaction was completed within short time period in high yields at room temp
- Kumar, Parvin,Kumar, Ashwani
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experimental part
p. 1287 - 1290
(2011/10/05)
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- Generation of nitrile oxides from oxime derivatives by the oxidation with ammonium hexanitratocerate(IV)
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Aromatic and aliphatic nitrile oxides are generated by the oxidation of α-hydroxyimino carboxylic acid with ammonium hexanitratocerate(IV). They react with olefinic and acetylenic dipolarophiles to give the corresponding cycloaddition products in good yield. The oxidation of α-oxo aldoximes also affords α-oxo carbonitrile oxides.
- Arai, Noriyoshi,Iwakoshi, Mitsuhiko,Tanabe, Katsuhiko,Narasaka, Koichi
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p. 2277 - 2285
(2007/10/03)
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- New method of in situ generation of nitrile oxides by MnO2 oxidation of aldoximes
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Manganese(IV) oxide (MnO2) was found to oxidize aldoximes to nitrile oxides. Nitrile oxides were trapped in situ with dipolarophiles to furnish 2- oxazolines. The best results were obtained with hydroximinoacetates as nitrile oxide precursors.
- Kiegiel, Jaroslaw,Poplawska, Magdalena,Jozwik, Julita,Kosior, Malgorzata,Jurczak, Janusz
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p. 5605 - 5608
(2007/10/03)
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- A new route to nitrile oxides from primary alkylhalides for in situ dipolar cycloadditions
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A new route to nitrile oxide preparation from primary alkylbromide, chloride, nitrite and their cycloadditions with olefins to form isoxazolines in a single pot are described.
- Maiti, Dilipkumar,Bhattacharya, Pranab K.
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p. 385 - 386
(2007/10/03)
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- Intermodular 1,3-dipolar cycloaddition of nitrite oxides with vinyl acetate and acrylonitrile
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Reaction of several nitrile oxides 2, isolated from the oxidative dehydrogenation of aldoximes by chloramine-T, with vinyl acetate and acrylonitrile proceeds in better yield than if the nitrile oxides are generated in situ. Solvent effects are also consid
- Lokanatha Rai,Hassner, Alfred
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p. 242 - 245
(2007/10/03)
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- An improved method for preparation of nitrile oxides from nitroalkanes for in situ dipolar cycloadditions
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A new method has been found for generation of nitrile oxides in situ from nitroalkanes under mild conditions. Thus, reaction of nitroalkanes 1 with di-tert-butyl dicarbonate (2) and 4-dimethylaminopyridine (3) as catalyst in the presence of dipolarophiles
- Basel, Yochai,Hassner, Alfred
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p. 309 - 312
(2007/10/03)
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- Generation of Nitrile Oxides via O-Tributylstannyl Aldoximes; Application to the Synthesis of Isoxazolines and Isoxazoles
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Nitrile oxides were generated readily by the reaction of aldoximes 1, with tert-butyl hypochlorite and bis(tributyltin) oxide.The reaction proceeded efficiently under mild conditions, in which O-stannylated aldoximes 2 are thought to be key intermediates.This reaction system was applicable to the one-pot syntheses of isoxazole derivatives 4 and 5 in the presence of dipolarophiles via a cycloaddition.
- Moriya, Osamu,Takenaka, Hideo,Iyoda, Masaichi,Urata, Yoshikiyo,Endo, Takeshi
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p. 413 - 418
(2007/10/02)
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- O-Ethoxycarbonyl Hydroximoyl Chloride as Nitrile Oxide Precursor
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O-Ethoxycarbonyl hydroximoyl chloride serves as a stable precursor for nitrile oxide and is converted into the 1,3-dipole when heated under reflux in pyridine.
- Shimizu, Tomio,Hayashi, Yoshiyuki,Furukawa, Nobuhiro,Teramura, Kazuhiro
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p. 318 - 320
(2007/10/02)
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- Synthesis of Isoxazolines and Isoxazoles via Generation of Nitrile Oxides from O-Stannyl Aldoximes
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The reactions of O-tributylstannyl aldoximes and active halogen compounds such as tert-butyl hypochlorite or N-bromosuccinimide, whereby nitrile oxides are generated effectively, are applied to the preparations of isoxazolines and isoxazoles via d
- Moriya, Osamu,Takenaka, Hideo,Urata, Yoshikiyo,Endo, Takeshi
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p. 1671 - 1672
(2007/10/02)
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- A Convinient Preparative Method of Nitrile Oxides by the Dehydration of Primary Nitro Compounds with Ethyl Chloroformate or Benzenesulfonyl Chloride in the Presence of Triethylamine
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Three nitrile oxides (MeOCOCN->O, PhCN->O, and EtCN->O) were effectively generated in situ by dehydration of the corresponding primary nitro compounds (RCH2NO2) with PhSO2Cl or ClCOOEt in the presence of triethylamine.Various cycloadducts were prepared by the reaction of them with dipolarophiles.Some advantages of these methods are described in comparison with other known methods.
- Shimizu, Tomio,Hayashi, Yoshiyuki,Shibafuchi, Hiroshi,Teramura, Kazuhiro
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p. 2827 - 2832
(2007/10/02)
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