5909-74-0Relevant articles and documents
Semi-synthesis of a novel hybrid isoxazolidino withaferin via chemoselective and diastereoselective 1,3-dipolar nitrone cycloaddition reaction
Mandal, Ramkrishna,Singh, Meenakshi,Krishnan, Amrutha A.V.,Dahat, Yogita H.,Bharitkar, Yogesh P.,Ravichandiran,Hazra, Abhijit
, p. 2208 - 2218 (2019/04/05)
A facile, atom-economic synthesis of isoxazilidino withaferin, a novel hybrid of withaferin A, has been accomplished via two-step reaction of nitrone synthesis followed by nitrone 1,3-dipolar cycloaddition. The reaction is highly chemoselective (preferent
A molecular electron density theory study to understand the interplay of theory and experiment in nitrone-enone cycloaddition
Acharjee, Nivedita,Banerji, Avijit
, (2020/04/29)
Abstract: [3 + 2] cycloaddition (32CA) reaction of C,N-diaryl nitrone with benzylidene acetone has been studied to analyse the mechanism, selectivity and polar character of this nitrone-enone cycloaddition. Topological analysis of the electron localization function (ELF) shows the absence of pseudoradical and carbenoid centre in the nitrone, which allows its classification as a zwitter-ionic (zw) type three atom component (TAC) and hence participation in zw- type cycloadditions is associated with high activation energy barriers. This 32CA reaction follows a one-step mechanism with asynchronous TSs. Endo/meta product is obtained as the major cycloadduct experimentally, which can be rationalized from its calculated lowest activation energy among the four possible reaction pathways. Global electron density transfer (GEDT) at the TSs predict the non-polar character of this 32CA reaction. Topological analysis of the ELF and QTAIM parameters was performed at the TSs. Finally, non-covalent interaction (NCI) gradient isosurfaces are computed to obtain a visualization of non-covalent interactions at the interatomic bonding regions. Graphic Abstract: The experimental and theoretical aspects of [3+2] cycloaddition reactions of C,N-diaryl nitronewith benzylidene acetone is described. The reaction is meta/endo selective and follows onestep mechanism with non-covalent interactions. The C-C and C-O bonds are generated throughcoupling of pseudoradical centers.[Figure not available: see fulltext.]
Synthesis of 2′,3′,4′-triaryl-5,6-dihydro-8H-spiro[indolizine-7,5′-isoxazolidin]-8-ones via 1,3-dipolar cycloaddition reaction involving (Z)-C-aryl-N-phenylnitrones
Li, Xiaofang,Li, Youfeng,Tang, Jin
, p. 1062 - 1066 (2020/10/02)
[Figure not available: see fulltext.] The 1,3-dipolar cycloaddition of C-aryl-N-phenylnitrones to 7-arylmethylidene-6,7-dihydroindolizin-8(5H)-ones afforded novel 2′,3′,4′-triaryl-5,6-dihydro-8H-spiro[indolizine-7,5′-isoxazolidin]-8-ones in moderate yield
Gold-Catalyzed Oxidative Aminocyclizations of Propargyl Alcohols and Propargyl Amines to Form Two Distinct Azacyclic Products: Carbene Formation versus a 3,3-Sigmatropic Shift of an Initial Intermediate
Chao, Tzu-Hsuan,Chen, Mu-Jeng,Liu, Rai-Shung,Raj, Antony Sekar Kulandai,Sasane, Amit Vijay
supporting information, p. 16932 - 16938 (2020/11/30)
Gold-catalyzed oxidations of propargyl alcohols with nitrones by using a P(tBu)2(o-biphenyl)Au+ catalyst, afforded bicyclic annulation products from the Mannich reactions of gold enolates. The same reactions of propargyl amines with nitrones by using the same gold catalyst gave distinct oxoarylation products. Our DFT calculations indicate that oxidation of propargyl alcohols with nitrones by using electron-rich gold catalysts lead only to gold carbenes, which can generate gold enolates or oxoarylation intermediates with enolate species having a barrier smaller than that of oxoarylation species.
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 and Antimicrobial Evaluation of New Pyrrolo-isoxazolidine Derivatives
Yusuf, Mohamad,Shehneela,Singh, Baldev
, p. 220 - 228 (2018/12/11)
In the present study, pyrrolo-isoxazolidines 3(a-l) and 4(a-e), 4g, 4i, 4j have been synthesized by using the 1,3-dipolar cycloaddition reactions of nitrones 1(a-l) with ester substituted N-aryl maleimide (2b). These heterocycles have been obtained in cis and trans diastereomeric forms. The structures of newly synthesized heterocycles have been confirmed from their spectroscopic parameters such as IR,1H NMR,13C NMR and ESI-MS. The in vitro antimicrobial evaluation of these compounds were also investigated. Most of the prepared heterocycles showed significant antimicrobial properties. C3-phenyl substituted products exhibited the remarkable antibacterial behaviours while C3-thienyl/furyl substituted heterocycles proved themselves potent antifungal agents.
Nitrone synthesis via pair electrochemical coupling of Nitro-Compounds with Benzyl Alcohol Derivatives
Salehzadeh, Hamid,Mashhadizadeh, Mohammad Hossein
, p. 9307 - 9312 (2019/07/08)
Here we report a paired electrochemical coupling of readily accessible nitro-compounds with benzyl alcohols to yield nitrone derivatives. In this work, electrochemical behavior of nitrobenzene and benzyl alcohol derivatives was studied by cyclic voltammetry and controlled potential coulommetry. Electrochemical reactions have been performed in aqueous/ethanol (or acetonitrile) solutions by employing common graphite electrodes and a simple controlled current protocol which can make this strategy more appealing than other conventional pathways.
A highly efficient and stereoselective cycloaddition of nitrones to N-arylitaconimides
Teterina, Polina S.,Efremova, Mariia M.,Sirotkina, Ekaterina V.,Novikov, Alexander S.,Khoroshilova, Olesya V.,Molchanov, Alexander P.
supporting information, (2019/08/26)
The 1,3-dipolar cycloaddition of keto- and aldonitrones with N-arylitaconimides proceeds regioselectively giving only 5-spiroisoxazolidines. In the case of aldonitrones the reaction proceeds with high diastereoselectivity. A range of the obtained adducts
Copper-Catalyzed Synthesis of Polysubstituted Pyrroles through [3+1+1] Cycloaddition Reaction of Nitrones and Isocyanides
Tian, Zhuang,Xu, Jiaojiao,Liu, Bingxin,Tan, Qitao,Xu, Bin
supporting information, p. 2603 - 2606 (2018/05/22)
An efficient, copper-catalyzed [3+1+1] cycloaddition reaction was developed for the expedient synthesis of pharmacologically interesting polysubstituted pyrroles from easily available nitrones and α-acidic isocyanides. The given approach features a new mo
Catalytic Transformations of Alkynes into either α-Alkoxy or α-Aryl Enolates: Mannich Reactions by Cooperative Catalysis and Evidence for Nucleophile-Directed Chemoselectivity
Sahani, Rajkumar Lalji,Patil, Manoj D.,Wagh, Sachin Bhausaheb,Liu, Rai-Shung
supporting information, p. 14878 - 14882 (2018/10/15)
The catalytic formation of gold enolates from alkynes, nitrones, and nucleophiles is described, and their Mannich reactions result in nucleophile-directed chemoselectivity through cooperative catalysis. For 1-alkyn-4-ols and 2-ethynylphenols, their gold-catalyzed nitrone oxidations afforded N-containing dihydrofuran-3(2H)-ones with syn selectivity. The mechanism involves the Mannich reactions of gold enolates with imines through an O-H-N hydrogen-bonding motif. For aryloxyethynes, their gold enolates react selectively with nitrones to deliver 3-alkylidenebenzofuran-2-ones, as controlled by a C-H-O hydrogen-bonding motif.
