1124-33-0Relevant articles and documents
Single component N-O chelated arylnickel(II) complexes as ethene polymerisation and CO/ethene copolymerisation catalysts. Examples of ligand induced changes to the reaction pathway
Desjardins, Sylvie Y.,Cavell, Kingsley J.,Hoare, Jason L.,Skelton, Brian W.,Sobolev, Alexander N.,White, Allan H.,Keim, Wilhelm
, p. 163 - 174 (1997)
Arylnickel(II) phosphine complexes containing substituted N-O bidentate ligands, of the type [NiR(N-O)L] [N-O = 4-nitropyridine-2-carboxylate (4-NO2-pyca), R = 0-tolyl, L = PPh3; N-O = 2-pyrazinecarboxylate (pyzca), R = 0-tolyl, L = PPh3; and N-O = 4-methoxypyridine-2-carboxylate (4-MeO-pyca), R = 0-tolyl, L = PPh3] have been prepared and characterised. Single crystal X-ray studies of the complexes [Ni(0-tolyl)(pyca)PPh3], 1, and the isomorphous analogue [Ni(0-tolyl)(4-NO2-pyca)PPh3], 3, show the expected square planar coordination about the nickel centres, with the pyridine nitrogens being trans to the phosphine ligand for both compounds. The coordination spheres of the two complexes are very similar, no elongation of the Ni-N bond for complex 3, which contains the 4-NO2-pyca ligand, being evident. In complex 3 the 0-tolyl ligand is disordered over two sites indicating the presence, in the solid state, of two conformers in which the 0-methyl groups of 0-tolyl are located to either side of the coordination plane. The complexes with substituted pyca ligands form single component catalysts for the conversion of ethene to high molecular weight polyethene and for the copolymerisation of ethene and carbon monoxide to polyketone under mild conditions. The nature of the product, whether predominantly high molecular weight polymer or a mixture of polymer and lower oligomer, is dependent on the basicity of the N-O chelate ligand. From an NMR study of the effect of added ethene on the complex [Ni(0-tolyl)(4-NO2-pyca)PPh3], a mechanism involving alkene promoted ligand dissociation is suggested.
Metal-Free, Phosphonium Salt-Mediated Sulfoximination of Azine N-Oxides: Approach for the Synthesis of N-Azine Sulfoximines
Aithagani, Sravan Kumar,Kumar, Mukesh,Yadav, Mahipal,Vishwakarma, Ram A.,Singh, Parvinder Pal
, p. 5886 - 5894 (2016/07/23)
Herein, we report a simple and metal-free method for the synthesis of N-azine sulfoximines by the nucleophilic substitution of azine N-oxides with NH-sulfoximines. The present method works at room temperature with wide functional group compatibility and gives several unprecedented N-azine sulfoximines. The reaction conditions were also found suitable with enantiopure substrates and furnished products without any racemization. It also finds an application in the sulfoximination of azine-based functional molecules such as 2,2′-bipyridine, 1,10-phenanthroline, and quinine.
Metal-free methylation of a pyridine N-oxide C-H bond by using peroxides
Li, Gang,Yang, Suling,Lv, Bingjie,Han, Qingqing,Ma, Xingxing,Sun, Kai,Wang, Zhiyong,Zhao, Feng,Lv, Yunhe,Wu, Hankui
supporting information, p. 11184 - 11188 (2015/11/27)
Metal-free methylation of a pyridine N-oxide C-H bond was developed using peroxide as a methyl reagent under neat conditions. Pyridine N-oxide derivatives with various groups (e.g., Cl, NO2, and OCH3) were all suitable substrates, and the desired products were obtained in moderate to excellent yields under standard conditions. Moreover, the methylation can be performed with a good yield on the gram-scale experiment. Tentative mechanistic studies show that the methylation is a classical radical process.
PROCESS FOR THE PREPARATION OF FAMPRIDINE
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Page/Page column 13, (2011/10/03)
The present invention relates to a process for the preparation of substantially pure fampridine compound of structural formula (I), (II), (III) comprising nitrifying pyridine-N-oxide hydrochloride with suitable nitrating agent; reducing with suitable reducing agent and purifying by recrystallizing in water followed by treating with an alkyl acetate solvent.
