16089-64-8Relevant academic research and scientific papers
Regio- and Enantioselective (3+3) Cycloaddition of Nitrones with 2-Indolylmethanols Enabled by Cooperative Organocatalysis
Li, Tian-Zhen,Liu, Si-Jia,Sun, Yu-Wen,Deng, Shuang,Tan, Wei,Jiao, Yinchun,Zhang, Yu-Chen,Shi, Feng
supporting information, p. 2355 - 2363 (2020/12/09)
The regio- and enantioselective (3+3) cycloaddition of nitrones with 2-indolylmethanols was accomplished by the cooperative catalysis of hexafluoroisopropanol (HFIP) and chiral phosphoric acid (CPA). Using this approach, a series of indole-fused six-membered heterocycles were synthesized in high yields (up to 98 %), with excellent enantioselectivities (up to 96 % ee) and exclusive regiospecificity. This approach enabled not only the first organocatalytic asymmetric (3+3) cycloaddition of nitrones but also the first C3-nucleophilic asymmetric (3+3) cycloaddition of 2-indolylmethanols. More importantly, theoretical calculations elucidated the role of the cocatalyst HFIP in helping CPA control the reactivity and enantioselectivity of the reaction, demonstrating a new mode of cooperative catalysis.
Crystal and molecular structure studies of (Z)-N-methyl-C-4-substituted phenyl nitrones by XRD, DFT, FTIR and NMR methods
Lasri, Jamal,Eltayeb, Naser Eltaher,Haukka, Matti,Alghamdi, Yousef
, p. 70 - 78 (2016/09/02)
(Z)-N-methyl-C-4-substituted phenyl nitrones –O+N(Me)=C(H)R (Z-2a R = 4-ClC6H4, Z-2b R = 4-NO2C6H4, Z-2c R = 4-CH3OC6H4) were synthesized and cha
A magnetoclick imidazolidinone nanocatalyst for asymmetric 1,3-dipolar cycloadditions
Pagoti, Sreenivasarao,Dutta, Debasish,Dash, Jyotirmayee
supporting information, p. 3532 - 3538 (2014/01/06)
A 1,3-dipolar azide-alkyne cycloaddition has been used to prepare a magnetic nanoparticle immobilized MacMillan catalyst that catalyzes the enantioselective 1,3-dipolar cycloaddition between nitrones and α,β-unsaturated aldehydes. The catalyst can be recovered and recycled for five consecutive runs without any significant loss in yields and diastereo- and enantioselectivities of the isoxazolidines. Copyright
N-tert-Butyl and N-methyl nitrones derived from aromatic aldehydes inhibit macromolecular permeability increase induced by ischemia/reperfusion in hamsters
Dias, Ayres G.,Santos, Carlos E.V.,Cyrino, Fatima Z.G.A.,Bouskela, Eliete,Costa, Paulo R.R.
experimental part, p. 3995 - 3998 (2009/10/17)
N-Alquil nitrones 1c and 3-6 were prepared from aromatic aldehydes and N-tert-butylhydroxylamine or N-methylhydroxylamine in good yields and soft conditions. Their protective effect against microvascular damages caused by ischemia/reperfusion in 'hamster
1,3-Dipolar cycloadditions. Part XVII: Experimental and theoretical spectroscopic investigations of C-aryl-N-methyl nitrones
Acharjee, Nivedita,Banerji, Avijit,Banerjee, Manas,Das, Tapas K.
body text, p. 1627 - 1637 (2010/06/17)
Detailed experimental and theoretical spectroscopic studies of C-aryl-N-methyl nitrones have been reported. The optimized geometries have been calculated by DFT/B3LYP level of theory with 6-31+G(d,p) basis set. The theoretically computed frontier orbital
Exploiting microwave-assisted neat procedures: synthesis of N-aryl and N-alkylnitrones and their cycloaddition en route for isoxazolidines
Andrade, Marta M.,Barros, Maria Teresa,Pinto, Rui C.
, p. 10521 - 10530 (2008/12/23)
Microwave irradiation allows increasing the speed of several reactions and also offers the possibility of eliminating poisoning organic solvents. In this work we report the microwave-assisted neat synthesis of α-phenyl-tert-butylnitrone (PBN) and other alkyl and aryl nitrones and also the rapid synthesis of isoxazolidines resulting from 1,3-dipolar cycloaddition of nitrones to ethyl trans-crotonate.
Oxidation of N-benzyl-N-methylhydroxylamines to nitrones. A mechanistic study
Hassan, Azfar,Wazeer, Mohammed I. M.,Ali, Sk. Asrof
, p. 393 - 399 (2007/10/03)
Oxidation of various N-(o-, m-, p- substituted benzyl)- N-methylhydroxylamines has been carried out using mercury(II) oxide and p-benzoquinone (p-BQ) as oxidants. Hammett plots have been obtained with negative ρ values, showing the development of a positive centre in the transition state. The unstable E nitrones, which readily isomerize to the more stable Z nitrones, are obtained in appreciable quantities and in some cases as the major product. A considerable deuterium isotope effect is observed in the oxidation process. The overall picture of the mechanistic pathway involves electron transfer from nitrogen to the oxidant followed by hydrogen abstraction.
Chromium and Tungsten Pentacarbonyl Groups as Reactivity and Selectivity Auxiliaries in Cycloaddition of Alkynyl Fischer Carbene Complexes with N-Alkyl Nitrones
Chan, Kin Shing,Yeung, Ming Lok,Chan, Wai-kin,Wang, Ru-Ji,Mak, Thomas C. W.
, p. 1741 - 1747 (2007/10/02)
Alkynyl Fischer carbene complexes were found to undergo chemoselective, regioselective, and rate-enhanced 1,3-dipolar cycloaddition with nitrones to give 2,3-dihydroisoxazole carbene complexes in excellent yields.These alkynyl complexes can serve as synth
