- Ring Expansion of Donor-Acceptor Cyclopropane via Substituent Controlled Selective N-Transfer of Oxaziridine: Synthetic and Mechanistic Insights
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A distinctive N-substituent controlled electrophilic N-transfer of oxaziridines with donor-acceptor cyclopropanes in the presence of MgI2 is reported. Contrary to earlier reports, the oxaziridine having bulkier N-substituents can also give N-transferred product instead of the O-transferred one. Interestingly, the oxaziridines having α-H containing N-substituents lead to the pyrrolidine derivatives through [3 + 2] cycloaddition. A mechanistic reasoning for this divergent reactivity is depicted by density functional theory calculations and validated through energy decomposition analysis.
- Ghosh, Asit,Mandal, Subhajit,Chattaraj, Pratim Kumar,Banerjee, Prabal
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supporting information
p. 4940 - 4943
(2016/10/18)
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- Photochemically-induced C-C bond formation between tertiary amines and nitrones
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Photoexcited nitrones serve as excellent electron acceptors as well as radical acceptors in the presence of tertiary amines to give β-amino hydroxylamines via photochemically-induced direct sp3 C-H functionalization of the tertiary amines. The combined use of an organophotosensitizer and photoirradiation was highly effective in accelerating addition reactions. Several nitrones and tertiary amines were successfully utilized to give β-amino hydroxylamines in good yield. Highly regioselective generation of primary α-aminoalkyl radicals based on Lewis's stereoelectronic rule and diastereoselective addition reactions of primary α-aminoalkyl radicals with nitrones were successfully achieved. Furthermore, a highly diastereoselective reaction of an α-aminoalkyl radical with a chiral (E)-geometry-fixed α-alkoxycarbonylnitrone was performed.
- Itoh, Kennosuke,Kato, Ryo,Kinugawa, Daito,Kamiya, Hideaki,Kudo, Ryuki,Hasegawa, Masayuki,Fujii, Hideaki,Suga, Hiroyuki
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supporting information
p. 8919 - 8924
(2015/08/24)
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- [Bmim]BF4-immobilized rhenium-catalyzed highly efficient oxygenation of aldimines to oxaziridines using solid peroxides as oxidants
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Various rhenium-based catalysts immobilized in [bmim]BF4 were found to be efficient for oxygenation of various aldimines to the corresponding oxaziridines in excellent yields under mild conditions using solid peroxides like UHP, SPC and SPB as oxidants. Among the various rhenium-based catalysts studied, MTO was found to be most efficient. The reusability and recyclability of MTO immobilized in [bmim]BF4 was established by using it for three subsequent cycles for oxygenation of benzylidine-tert-butylamine using UHP as oxidant.
- Jain, Suman L.,Singhal, Sweety,Sain, Bir
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p. 2930 - 2935
(2008/02/02)
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- An environmentally friendly oxidation system for the selective oxygenation of aldimines to oxaziridines with anhydrous TBHP and alumina-supported MoO 3 as a recyclable heterogeneous catalyst
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A highly efficient and selective protocol for the oxygenation of various aldimines to oxaziridines, which proceeds in excellent yields with enhanced selectivity by using alumina-supported M0O3 as a recyclable heterogeneous catalyst and anhydrous TBHP as the ultimate oxidant, is described. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Singhal, Sweety,Jain, Suman L.,Prasad,Sain, Bir
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p. 2051 - 2054
(2008/02/04)
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- Simple and highly efficient synthesis of oxaziridines by tetrabutylammonium Oxone
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Oxygenation of various aldimines with tetrabutylammonium monoperoxysulfate produced the corresponding E- or a mixture of E- and Z-oxaziridines with very high yields (≥90%) and good to excellent selectivities (75-100%) within 20min to 10h in CH3CN at room temperature (~25°C). The E/Z isomer ratio critically depends on the stereo-electronic nature of the substituents in the oxaziridines, solvent, and the presence of Lewis acids and bases.
- Mohajer, Daryoush,Iranpoor, Nasser,Rezaeifard, Abdolreza
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p. 631 - 634
(2007/10/03)
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- Action d'un Tetrafluoroborate d'Oxaziridinium sur les Amines et les Imines
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The Oxaziridinium salt 1 derived from dihydroisoquinolin is an oxygen transfer reagent to primary amines leading to nitrosoderivatives (if R = Alkyl) or nitro compounds (if R = Aryl), to tertiary amines leading to N-oxides, and to secondary amines and imines leading to the corresponding nitrone.
- Hanquet, Gilles,Lusinchi, Xavier
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p. 12185 - 12200
(2007/10/02)
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- The Synthesis of NH Aldimines and Derivatives by Spontaneous and Base-catalysed Decomposition of Oxaziridines
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A range of oxaziridines containing N-methylene substituents has been synthesized by peracid oxidation of the corresponding fluorenylidene N-alkylamines.Spontaneous and tertiary amine base-catalysed decomposition of the oxaziridines into unstable NH aldimines and derivatives was observed.Acrylaldehyde, 2-methylacrylaldehyde, and benzaldehyde NH imines have been identified as initial products from decomposition of the corresponding oxaziridines. 2,4,6-Trialkylhexahydro-1,3,5-triazines, N,N'-dialkylidene-1,1-diaminoalkanes, N,N'-diarylidene-1,1-diaminoalkanes, and N-isobutylidene-2-methylpropenylamine were among the isolated products formed via the undetected alkyl aldehyde NH imines resulting from oxaziridine decomposition.
- Boyd, Derek R.,Coulter, Peter B.,Hamilton, Robert,Thompson, Norris T.,Sharma, Narain D.,Stubbs, Michael E.
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p. 2123 - 2128
(2007/10/02)
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- Relative Conjugative Abilities of Three-Membered Ring Heterocycles with Benzene Based on 13C and 15N NMR
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The conjugative ability of various three-membered rings with benzene was investigated by observing the sensitivity of β-carbon 13C chemical shifts to para substituents.These Hammett ρ values were 2.0, 1.5, 1.0, and 0.9 ppm for arylcyclopropanes, N-methyl-2-arylaziridines, phenyloxiranes, and N,N-dimethyl-2-arylaziridinium fluorosulfonates, respectively.These values were intermediate to ones for para-substituted styrenes (6.5 ppm) and ethylbenzenes (-0.9 ppm), model compounds which were taken to represent extremes of conjugative ability.Similar results were found for 15N chemical shifts of trans-3-aryl-oxaziridines, which had a slope of 2.1 ppm, intermediate to those for benzylimines (20.2 ppm) and benzylamines (-1.3 ppm).The order of conjugative ability, which decreases with increasing electronegativity of the hetero group, could not be explained by hybridization changes based on comparing open chain analoques with the above compounds or by conformational factors.The trend can, however, be interpreted qualitatively by perturbation theory which shows that more electronegative hetero groups decrease the extent of interaction between aryl-? and cyclopropane orbitals as well as cross ring conjugation.
- Crist, DeLanson R.,Jordan, Guy J.,Moore, Donald W.,Hashmall, Joseph A.,Borsetti, Arnold P.,Turujman, Saleh A.
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p. 4136 - 4142
(2007/10/02)
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- Asymmetric Synthesis at Nitrogen by Oxidation of Imines with m-Chloroperbenzoic Acid in the Presence of Optically Active Carbinols. Absolute Stereochemistry of Chiral Alcohol-Imine-Peracid Solvates
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Optically active oxaziridines, stable at the asymmetric nitrogen atom, have been obtained by oxidation of imines with m-chloroperbenzoic acid in the presence of chiral carbinols.The optical purity of the reaction products increases on decreasing the tempe
- Bucciarelli, Maria,Forni, Arrigo,Moretti, Irene,Torre, Giovanni
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p. 2152 - 2161
(2007/10/02)
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