3376-24-7Relevant articles and documents
The Reaction of Nitrogen Dioxide with N-Benzylidene-t-butylamine N-Oxide. Formation of a White Solid Adduct and Its Properties
Sonokawa, Koji,Machida, Hidenori,Sakakibara, Kazuhisa,Hirota, Minoru
, p. 207 - 210 (1992)
The reaction of N-benzylidene-t-butylamine N-oxide (PBN) with NO2 gave white diamagnetic solid C11H16N2O4 in addition to greenish blue free radical species.The white solid was shown to decompose quantitatively into the starting PBN and nitric acid when it was dissolved in water.
Control of methyl methacrylate radical polymerization via Enhanced Spin Capturing Polymerization (ESCP)
Zang, Lin,Wong, Edgar H.H.,Barner-Kowollik, Christopher,Junkers, Thomas
, p. 3821 - 3825 (2010)
The nitrone mediated polymerization of methyl methacrylate (MMA) via the enhanced (termination) spin capturing polymerization (ESCP) process is made possible via the addition of small amounts of styrene (between 5 and 10 vol.%) to the reaction mixture. Efficient control over the molecular weight between 7000 and 57,000 g mol-1 (at 60 °C) yields macromolecules that feature a mid-chain alkoxyamine functionality and are rich in methyl methacrylate. The collated kinetic and molecular weight data allow for a deduction of the spin capturing constant, CSC, in the range between 0.15 and 0.30. During the ESCP process, the number average molecular weight, Mn, of the formed mid-chain functional polymer is constant up to high monomer to polymer conversions (i.e. 80%). The high degree of alkoxyamine mid-chain functionality present in the generated polymeric material is evidenced via a subsequent nitroxide-mediated polymerization process employing the formed ESCP polymer, indicating a chain extension from 37,700 to 118,000 g mol-1 with a concomitant reduction in polydispersity (from 2.3 to 1.5).
Weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis
Park, Jin,Park, Sehoon,Jang, Gwang Seok,Kim, Ran Hui,Jung, Jaehoon,Woo, Sang Kook
, p. 9995 - 9998 (2021/10/06)
The selective rearrangement of oxaziridines to amidesviaa single electron transfer (SET) pathway is unexplored. In this study, we present a weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis. The developed method shows excellent functional group tolerance with a broad substrate scope and good to excellent yields. Furthermore, control experiments and density functional theory (DFT) calculations are performed to gain insight into the reactivity and selectivity.
The effect of viscosity on the coupling and hydrogen-abstraction reaction between transient and persistent radicals
Li, Xiaopei,Kato, Tatsuhisa,Nakamura, Yasuyuki,Yamago, Shigeru
supporting information, p. 966 - 972 (2021/04/29)
The effect of viscosity on the radical termination reaction between a transient radical and a persistent radical undergoing a coupling reaction (Coup) or hydrogen abstraction (Abst) was examined. In a non-viscous solvent, such as benzene (bulk viscosity bulk 99% Coup/Abst selectivity, but Coup/Abst decreased as the viscosity increased (89/11 in PEG400 at 25 °C [bulk = 84 mPa s]). While bulk viscosity is a good parameter to predict the Coup/Abst selectivity in each solvent, microviscosity is the more general parameter. Poly(methyl methacrylate) (PMMA)-end radicals had a more significant viscosity effect than polystyrene (PSt)-end radicals, and the Coup/Abst ratio of the former dropped to 50/50 in highly viscous media (bulk = 3980 mPa s), while the latter maintained high Coup/ Abst selectivity (84/16). These results, together with the low thermal stability of dormant PMMA-TEMPO species compared with that of PSt-TEMPO species, are attributed to the limitation of the nitroxide-mediated radical polymerization of MMA. While both organotellurium and bromine compounds were used as precursors of radicals, the former was superior to the latter for the clean generation of radical species.
Metal-Free Solvent Promoted Oxidation of Benzylic Secondary Amines to Nitrones with H2O2
Adrio, Javier,Amarante, Giovanni Wilson,Granato, álisson Silva
, p. 13817 - 13823 (2021/10/01)
An environmentally benign protocol for the generation of nitrones from benzylic secondary amines via catalyst-free oxidation of secondary amines using H2O2 in MeOH or CH3CN is described. This methodology provides a selective access to a variety of C-aryl nitrones in yields of 60 to 93%. Several studies have been performed to shed light on the reaction mechanism and the role of the solvent.
S -Tetrazine: Robust and Green Photoorganocatalyst for Aerobic Oxidation of N,N-Disubstituted Hydroxylamines to Nitrones
Allain, Clémence,Audebert, Pierre,Claraz, Aurélie,Le, Tuan,Lyu, Jiyuan,Masson, Géraldine
supporting information, (2021/12/06)
Efficient photocatalytic aerobic oxidative dehydrogenation reactions of N,N-disubstituted hydroxylamines to nitrones were developed with an in situ generated photocatalyst based on commercially available 3,6-dichlorotetrazine. This process affords a wide range of nitrones in high yields under mild conditions. In addition, an oxidative (3+3) cycloaddition between an oxyallyl cation precursor and a hydroxylamine was also developed.
Aliphatic nitro compounds chemistry: oximes–nitrones tunable production through directed tandem synthesis
Kazemi, Foad,Ramdar, Moosa,Davarpanah, Jamal
, p. 353 - 362 (2019/01/25)
Abstract: Reduction of aliphatic nitro compounds in the presence of aldehydes and dialdehydes for tunable directed synthesis of oximes, nitrones, nitrone–oximes, and dinitrones was reported. The slow and nonselective reduction of aliphatic nitro compounds was directed by condensation of in situ prepared alkylhydroxylamines with aromatic aldehydes. Mononitrones and dinitrones were synthesized at reflux and at 55?°C conditions, respectively, in tetrahydrofuran using SnCl2?2H2O and Na2CO3. It was found that the presence of a catalytic amount of carboxylic acid such as 3-phenylpropanoic acid increases the yield of dinitrones versus nitrone–oxime and dioxime when dialdehydes were used as aldehyde source. Graphical abstract: [Figure not available: see fulltext.].
Accessing benzooxadiazepines: Via formal [4 + 3] cycloadditions of aza- o -quinone methides with nitrones
Zheng, Yong-Sheng,Tu, Liang,Gao, Li-Mei,Huang, Rong,Feng, Tao,Sun, Huan,Wang, Wen-Xuan,Li, Zheng-Hui,Liu, Ji-Kai
, p. 2639 - 2642 (2018/04/27)
An unprecedented and efficient [4 + 3] cycloaddition of N-(ortho-chloromethyl)aryl amides with nitrones has been developed. This approach provides easy access to a series of seven-membered benzooxadiazepine derivatives in good to excellent yields (up to 99% yield) under mild reaction conditions.
Light-induced formation of nitroxyl radicals by organic Bi(V) compounds in the presence of 2-methyl-2-nitrosopropane and C-phenyl-N-tert-butylnitrone
Gushchin,Kalistratova,Maleeva,Dodonov,Kosov, D. Yu.,Emel’yanov,Kuropatov
, p. 1547 - 1549 (2017/09/01)
The organic bismuth compounds Ph3Bi(O2CCH=CHCH3)2 and Ph3Bi(O2CEt)2 decompose under scattered light in the presence of spin traps (2-methyl-2-nitrosopropane and C-phenyl-N-tert-butylnitrone) in organic solvents (acetonitrile, benzene, toluene) to form adducts of phenyl radicals with the traps.
Dual Role of Pyrrolidine and Cooperative Pyrrolidine/Pyrrolidinium Effect in Nitrone Formation
Morales, Sara,Guijarro, Fernando G.,Alonso, Inés,García Ruano, José Luis,Cid, M. Belén
, p. 84 - 91 (2016/01/12)
The formation of nitrones by direct condensation between equimolecular amounts of N-substituted hydroxylamine hydrochlorides and aromatic or aliphatic aldehydes is efficiently promoted by pyrrolidine in a matter of minutes under very mild conditions in almost quantitative yields after a simple filtration through a short pad of silica gel. According to theoretical, spectroscopic, and experimental studies, this success is due to the ability of pyrrolidine to liberate the hydrochloride of the hydroxylamine and catalyze the reaction via iminium activation ion. Moreover, a cooperative pyrrolidine/pyrrolidinium chloride effect facilitates several steps of the catalytic cycle through proton transfer without hampering the nucleophilicity of the hydroxylamine by protonation.
