3376-26-9Relevant articles and documents
S -Tetrazine: Robust and Green Photoorganocatalyst for Aerobic Oxidation of N,N-Disubstituted Hydroxylamines to Nitrones
Lyu, Jiyuan,Le, Tuan,Claraz, Aurélie,Allain, Clémence,Audebert, Pierre,Masson, Géraldine
supporting information, p. 177 - 181 (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.
Sc(OTf)3-catalyzed [3 + 2]-cycloaddition of nitrones with ynones
He, Chun-Ting,Han, Xiao-Li,Zhang, Yan-Xue,Du, Zhen-Ting,Si, Chang-Mei,Wei, Bang-Guo
, p. 457 - 466 (2021/01/29)
An efficient approach to access functionalized (2,3-dihydroisoxazol-4-yl) ketones has been developed by reacting nitrones 4 with ynones 7 or terminal ynones 10 in a one-pot fashion. The reaction went through a formal Sc(OTf)3-catalyzed [3 + 2]-cycloaddition process to generate a number of functionalized (2,3-dihydroisoxazol-4-yl) ketones 11aa-11aw, 11ba-11la and 12aa-12ae in moderate to good yields. This journal is
Dynamics in Catalytic Asymmetric Diastereoconvergent (3 + 2) Cycloadditions with Isomerizable Nitrones and α-Keto Ester Enolates
Ezawa, Tetsuya,Sohtome, Yoshihiro,Hashizume, Daisuke,Adachi, Masaya,Akakabe, Mai,Koshino, Hiroyuki,Sodeoka, Mikiko
supporting information, p. 9094 - 9104 (2021/07/01)
Reaction design in asymmetric catalysis has traditionally been predicated on a structurally robust scaffold in both substrates and catalysts, to reduce the number of possible diastereomeric transition states. Herein, we present the stereochemical dynamics in the Ni(II)-catalyzed diastereoconvergent (3 + 2) cycloadditions of isomerizable nitrile-conjugated nitrones with α-keto ester enolates. Even in the presence of multiple equilibrating species, the catalytic protocol displays a wide substrate scope to access a range of CN-containing building blocks bearing adjacent stereocenters with high enantio- and diastereoselectivities. Our computational investigations suggest that the enantioselectivity is governed in the deprotonation process to form (Z)-Ni-enolates, while the unique syn addition is mainly controlled by weak noncovalent bonding interactions between the nitrone and ligand.
Method for preparing N -benzylhydroxylamine hydrochloride with high yield
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Paragraph 0076; 0078-0082, (2021/08/25)
The invention discloses a method for preparing N - benzylhydroxylamine hydrochloride in a high yield, which comprises the following steps: S01, taking dibenzylamine as a starting raw material, adding a solvent, a catalyst and dropwise adding first oxidant
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.
A straightforward synthesis of a new family of molecules: 2,5,8-trialkoxyheptazines. Application to photoredox catalyzed transformations
Le, Tuan,Galmiche, Laurent,Masson, Géraldine,Allain, Clémence,Audebert, Pierre
supporting information, p. 10742 - 10745 (2020/10/02)
We have prepared several 2,5,8-trialkoxyheptazines starting from the soluble precursor 2,5,8-tris(3,5-diethylpyrazolyl)-heptazine. We present their synthesis along with their promising spectroscopic and electrochemical properties, which demonstrate large
Alloxan-catalyzed biomimetic oxidations with hydrogen peroxide or molecular oxygen
Zhang, Shiqi,Li, Guangxun,Li, Ling,Deng, Xiongfei,Zhao, Gang,Cui, Xin,Tang, Zhuo
, p. 245 - 252 (2019/12/24)
Inspired by biological flavin catalysis, the nonionic alloxan derivatives were applied as the biomimetic catalysts for various oxidations, catalyzing oxidations of sulfides and amines with hydrogen peroxide or molecular oxygen under mild conditions with high yields in a short time. The whole catalytic cycle has been verified to be a biomimetic approach through the formation of the alloxan hydroperoxide reactive intermediate. Additionally, encouraging asymmetric catalytic results have been obtained with an easily prepared chiral alloxan in a sulfoxidation reaction.
Nucleophilic Addition to Nitrones Using a Flow Microreactor
Arakawa, Yukihiro,Imada, Yasushi,Minagawa, Keiji,Okamoto, Takuma,Ueta, Shun
supporting information, p. 866 - 870 (2020/05/28)
Nucleophilic addition reactions of soft carbon nucleophiles to nitrones in a flow microreactor are reported for the first time. Under microflow conditions at 30 to 0 °C, a range of nitrones can be efficiently transformed into the corresponding oxyiminium ions by reaction with either acyl halides or trialkylsilyl triflates. These can subsequently undergo the addition of nucleophiles including allyltributylstannane, ketene methyl tert-butyldimethylsilyl acetal, and N-silyl ketene imines to afford the corresponding adducts in high yields; such reactions at a similar temperature under batch conditions resulted in lower yields because of undesired side reactions.
A green synthesis of nitrones in glycerol
Shariatipour, Monire,Jadidinejad, Masoumeh,Heydari, Akbar
, (2019/11/11)
Abstract: An eco-friendly and efficient synthesis of nitrones is presented by condensation of an equimolar amount of aldehydes and N-substituted hydroxylamine hydrochlorides in glycerol as a recyclable solvent-catalyst. This novel protocol provides rapid and mild access to a series of nitrone derivatives in good to excellent yields in the absence of catalyst and base. Graphic abstract: SYNOPSIS In this study, a base-free protocol by using glycerol as the solvent-catalyst was applied for an eco-friendly synthesis of nitrones from the condensation of aldehydes and N-substituted hydroxylaminehydrochlorides.[Figure not available: see fulltext.].
Synthesis of 1,2,4-oxadiazolidines via [3+2] cycloaddition of nitrones with carbodiimides
Chen, Yuan,Fuyue, Liuting,Wang, Gangqiang,Wang, Hang,Lu, Chun,Guo, Haibing,St. Amant, Chiara,Sun, Shaofa,Xing, Yalan
supporting information, p. 4329 - 4332 (2019/03/19)
An efficient [3+2] cycloaddition of nitrones and carbodiimides has been developed. This 1,3-dipolar cycloaddition features high regioselectivity, mild and metal-free conditions, excellent functional group compatibility, and a broad substrate scope. The X-ray structures of two regio-isomers confirmed the regioselectivity of this transformation.
