- Iron-Enabled Utilization of Air as the Terminal Oxidant Leading to Aerobic Oxidative Deoximation by Organoselenium Catalysis
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In contrast to conventional organoselenium-catalyzed oxidation reactions that require peroxide oxidants such as hydrogen peroxide, in this work we found that, addition of a low loading of iron (II) could enable the successful utilization of air as the terminal oxidant in organoselenium-catalyzed oxidative deoximation reaction of ketoximes. This led to a new mild and relatively green aerobic oxidative deoximation method. Control reactions and X-ray photoelectron spectroscopy (XPS) analysis suggest that iron is crucial in the catalytic cycle, working to prohibit the deactivation of selenium catalyst through an iron-catalyzed aerobic oxidation of low valent selenium species by air to the active high valent selenium species. Since air can be utilized as the terminal oxidant, this work may contribute to the advance of organoselenium catalysis. (Figure presented.).
- Chen, Chao,Zhang, Xu,Cao, Hongen,Wang, Fang,Yu, Lei,Xu, Qing
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p. 603 - 610
(2018/12/14)
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- Cephalosporins with sulfur-containing oxyimino side chain
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Antibacterial compounds of the formula STR1 wherein R is a mononuclear carbocyclic aromatic group, a 5-membered aromatic heterocyclic group which contains as the hetero (non-carbon) ring member(s) an oxygen or sulphur atom or an imino or lower alkylimino group and, optionally, one or two nitrogen atoms, or a 6-membered aromatic heterocyclic group which contains one to three nitrogen atoms as the hetero ring member(s); R1 is hydrogen or a 3-substituent which is usable in cephalosporin chemistry; A is lower alkylene or C3-7 -cycloalkylene which is optionally substituted with carboxy, carbamoyl, lower alkylcarbamoyl or di(lower alkyl)carbamoyl; Q is lower alkylene or C3-7 -cycloalkylene which is optionally substituted with carboxy, carbamoyl, lower alkylcarbamoyl or di(lower alkyl)carbamoyl, or the group --NR2 -- or --NR2 NR3 --; R2 and R3 are independently hydrogen or lower alkyl; p and m are the zero or 1, n is zero, 1 or 2; R4 is hydrogen, lower alkanoyl or tri(lower alkyl)silyl; two R4 groups together represent diphenylmethylene; R5 is hydrogen, lower alkyl, hydroxy, lower alkoxy, halogen, nitro, --OCOR7, --OCOOR71, --N(R7)2, --NHCOR7, --NHCOOR71, --COR7, --SR7, --SOR7, --SO2 R7, --SO3 H, --COOR7 or --CON(R7)2 ; R6 is hydrogen, lower alkyl or halogen, R7 is hydrogen or lower alkyl; R71 is lower alkyl, and the two --OR4 groups are attached to the phenyl ring via adjacent carbon atoms, as well as readily hydrolyzable esters and pharmaceutically acceptable salts of these compounds and hydrates of compounds of formula I and of their esters and salts.
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- Syn isomer of 7-[2-cyclo(lower) alkoxyimino-2-(2-amino-or substituted aminothiazol-4-yl)acetamido]-3-lower alkanoyloxymethyl or heterocyclicthiomethyl-3-cephem-4-carboxylic acid compounds
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Syn isomers of 3-substituted 7-[2-substituted imino-2-substituted acetamido]-3-cephem-4-carboxylic acid and salt bacteriostatic-compounds and pharmaceutical compositions thereof and processes for preparing same.
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- 7-[2-(2-Aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido] cephalosporins
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A 7-[2-(2-aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido] cephalosporin derivative of the formula; STR1 wherein R3 is hydrogen or a residue of a nucleophilic compound; R2 NH is an amino group which may optionally be protected, pharmaceutically acceptable salt or ester thereof, is found to have excellent anti-bacterial activity against a broad spectrum of bacteria inclusive of gram-negative bacteria such as Escherichia coli, Serratia marcescens, Proteus rettgeri, Enterobacter cloacae and Citrobacter freundii. Thus, this compound may be used for an antibacterial agent in therapeutical purposes.
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- Syn-isomer of 3,7-disubstituted-3-cephem-4-carboxylic acid compounds and processes for the preparation thereof
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Preparation of pharmaceutical composition comprising, treatment of human and animal diseases with, and compound of, 3,7-disubstituted-3-cephem-4-carboxylic acid.
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- Syn-isomers of 7-[2-alkoxyimino-2-(2-amino-thiazol-4-yl)acetamido]-3-[nitrobenzoyl-, or benzoyl-oxymethyl]-3-cephem-4-carboxylic acid
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New syn-isomers of 3-cephem-4-carboxylic acids having anti-bacterial activities, processes for preparation thereof, pharmaceutical compositions thereof, with the acids being substituted at the 3 position with acyloxymethyl, hydroxymethyl, formyl or heterocyclic thiomethyl groups and at the 7 position with alkoxyiminoacetamido substituted with substituted phenyl or substituted thiazolyl.
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- Cephem derivative
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Cephem derivatives of the general formula STR1 in which the R2 O group is in the syn-position, a process for their manufacture and pharmaceutical formulations which are active against bacterial infections and contain these compounds.
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- Syn 7-oxoimino substituted derivatives of cephalosporanic acid
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The present invention relates to new syn-isomer of 3,7-disubstituted-3-cephem-4-carboxylic acid compounds and pharmaceutically acceptable salts thereof. More particularly, it relates to new syn-isomer of 3,7-disubstituted-3-cephem-4-carboxylic acid compounds and pharmaceutically acceptable salts thereof which have antibacterial activities and to processes for the preparation thereof, to pharmaceutical composition comprising the same, and to a method of using the same therapeutically in the treatment of infectious diseases in human beings and animals.
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