نتایج جستجو برای: nitrones

تعداد نتایج: 453  

2016
Amer A. Taqa

Some new metal(II) dichloride complexes with the ligands substituted nitrones of the general formula [ML2Cl2], where M= Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), L=OCH=CHCH=C-CH=N(O)C6H4X (X=H,p-CH3,CH3O,CH3CO,F,Cl,and Br) have been prepared and characterized by elemental analysis, IR,H,C NMR and Vis/Uv spectroscopy. The IR spectral data showed that the nitrone ligands coordinated with the met...

2010
Fabian Pfrengle Hans-Ulrich Reissig

A stereodivergent synthesis of enantiopure 3,6-dihydro-2H-pyrans is presented. The addition of lithiated enol ethers to carbohydrate-derived nitrones afforded syn- or anti-configured hydroxylamine derivatives 4a-d that were cyclized under Lewis acidic conditions to yield functionalized dihydropyrans cis- or trans-5a-d containing an enol ether moiety. This functional group was employed for a var...

2003
Langu Peng Cunxiang Chen Christian R. Gonzalez

We report the syntheses of antifungals containing the novel pharmacophores: oxaziridines, sulfonyloxaziridines, nitrones and nitronyl nitroxides. We hypothesized that multiple copies of the pharmacophore per molecule might be a prerequisite to enhance efficacy against the opportunistic pathogen, Pneumocystis carinii. Therefore structural optimization of the leads was based on this new “multival...

2014
Oliver Goerz Helmut Ritter

Isosorbide was esterified with acryloyl chloride and crotonic acid yielding isosorbide diacrylate (9a) and isosorbide dicrotonate (9b), which were reacted with benzaldehyde oxime in the presence of zinc(II) iodide and boron triflouride etherate as catalysts to obtain N-alkylated dinitrones 10a/b. Poly(isosorbide itaconite -co- succinate) 13 as a bio-based unsaturated polyester was cross-linked ...

2017
Zhaobing Guan Manman Ding Yao Sun Sisi Yu Ao Zhang Shuguang Xia Xiaosong Hu Yawei Lin

Herein, twoN-substituted coumaryl hydroxylamines (compounds 1a and 1b) with long aliphatic chains were prepared in 8 steps with a novel synthetic protocol. They served as derivatization agents for aldehydes by the formation of nitrones under mild conditions, which can be readily analysed by LC-MS with good chromatographic performance, excellent fluorescent response, and high ionization strength...

Journal: :Organic & biomolecular chemistry 2010
Mathilde Triquigneaux Laurence Charles Christiane André-Barrès Béatrice Tuccio

The spontaneous addition of air oxygen to a dienolic compound, yielding a cyclic peroxide, was followed by spin trapping (ST) combined with EPR spectroscopy and mass spectrometry (MS). Using two different nitrones, the ST/EPR study allowed the detection of the spin adduct of a radical intermediate, and the radical centre in the addend was identified after similar experiments performed with two ...

2006
Mahendra Gulla Lars Bierer Stefan Schmidt Volker Jäger

The cyclization of a ribose-derived pentenose oxime with various halogen electrophiles showed bromine to be the most effective reagent, leading to 80% of L-lyxo/D-ribo-pyrroline N-oxides in an 84:16 diastereomeric ratio. In order to explore the scope of this facile process, several other γ ,δ unsaturated oximes were submitted to this reaction. Depending on the substitution pattern, 23 – 87%, yi...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید