نتایج جستجو برای: alkyl group
تعداد نتایج: 991429 فیلتر نتایج به سال:
A number of small molecules, commonly described as autacoids, are extremely important mediators of inflammation. Among the autacoids are a group of lipid mediators called eicosanoids, which are derivatives of the 20-carbon polyunsaturated fatty acid (PUFA), arachidonic acid. Platelet activating factor (PAF), another important lipid mediator of inflammation, is 1-O-alkyl-2(R)-acetylglycero-3-pho...
Directly acting mutagens formed from N-nitroso-N-(formylmethyl)alkylamines (3) were isolated and identified as N-nitroso-N-alkyl-1-hydroxyimino-2-oxoethylamines (4). Their structures were elucidated on the basis of nuclear magnetic resonance spectra and confirmed by derivatization to the crystalline 2,4-dinitrophenylhydrazones (5). Compounds 4 (alkyl =ethyl and butyl) were strongly mutagenic to...
The substitution of aqua ligands of mononuclear Pt(II) complexes of the general form [Pt(H(2)O)(N,N-bis(2-pyridylmethyl)-N(CH(2))(n)-CH(3); -NC(CH(3))(3); -NH](CF(3)SO(3))(2), n = 1 (bpea); 2 (bppa); 3 (bpba); 5 (bpha), 9 (bpda) -NC(CH(3))(3) (bpbta) and -NH (bpma) by thiourea nucleophiles was investigated under pseudo first-order conditions as a function of concentration and temperature using ...
A series of Ru(II) (η(6)-arene) complexes with 1,2,3-triazolylidene ligands comprising different aryl and alkyl wingtip groups have been prepared and characterized by NMR spectroscopy, microanalysis, and in one case by X-ray diffraction. All complexes are active catalyst precursors for the oxidation of alcohols to the corresponding aldehydes/ketones without the need of an oxidant or base as add...
poly (vinylpyrrolidone)-grafted silica as an organic-inorganic hybrid material was used as an effective heterogeneous polymeric cosolvent catalyst in organic reactions. this modified silica catalyzed nucleophilic displacement of alkyl halides for easy preparation of alkyl thiocyanates, alkyl cyanides, alkyl azides and alkyl aryl ethers. furthermore, the catalyst was applied for the conversion o...
Tetraalkylammonium salts, characterized by an aromatic system pending from one of the alkyl chains, are taken as model systems to study the spectroscopic and redox properties of the aromatic centre under the field effects exerted by the charged group through alkyl bridges of varying length. The changes in the aromatic's redox properties, due to the net field effect and its different components,...
The class of compounds (RCp)2MX2, where M is a group IV metal, Cp is cyclopentadienyl, R is an alkyl, and X is a halide, has been of continuing interest as precursors for olefin coordination polymerization catalysts. In this communication, we demonstrate that the technique of optically detected magnetic resonance (ODMR) reveals subtle differences in the composition of the frontier molecular orb...
Abstract Chiral aliphatic amine and alcohol derivatives are ubiquitous in pharmaceuticals, pesticides, natural products fine chemicals, yet difficult to access due the challenge differentiate between spatially electronically similar alkyl groups. Herein, we report a nickel-catalyzed enantioselective hydroalkylation of acyl enamines enol esters with halides afford enantioenriched α-branched amin...
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