Cyclohexanone
Mostrando 13-24 de 41 artigos, teses e dissertações.
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13. Oxidação de hidrocarbonetos com peroxido de hidrogenio catalisada por renio em fase homogenea e heterogenea
Nowadays, there has been an increasing number of studies on the oxidation of organic compounds such as olefins, phenols, anisols, alcohols and alkanes catalyzed by rhenium complexes. In the first part of this work, the oxidation of hydrocarbons with anhydrous hydrogen peroxide, catalyzed by CH3ReO3, using acetonitrile as a solvent at 80°C was studied. In th
Publicado em: 1999
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14. Oxidação de cicloexano por terc-butil hidroperoxido catalisada por complexos de ferro (III) e cobre (II) soluveis em cicloexano
Cyclohexane oxidation by tert-butyI hydroperoxide in the presence of Fe(tma)3, Fe(fod)3, Cu(tma)2 and [Cu(en)2](NO3)2 was studied under reflux and under an oxygen pressure of 25 bar at 70°C. The iron catalysts produced cyclohexanone and cyclohexanol as main products, while the copper catalysts form cyclohexene as well. Over-oxidation produts were formed in
Publicado em: 1997
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15. Oxidação catalitica de cicloexano com peroxido de hidrogenio em condições ambientais
The oxidation of cyclohexane by the GoAgg system (FeCl3.6H2O, H2O2, pyridine, acetic acid) was studied at ambient conditions. The principal product obtained is cyclohexanone together with some cyclohexanol. The turnover number, the selectivity (ONE/OL) and the efficiency with respect to hydrogen peroxide were studied as a function of the temperature, the qua
Publicado em: 1992
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16. Oxidação biomimetica de cicloexano por peroxido de hidrogenio catalisada por sais de cobre (II)
Cyclohexane was oxidized by the GoChAgg system (pyridine, copper (II) salt, H2O2 under ambient conditions. The only reaction product was cyclohexanone. Efficiency and turnover number were studied as a function of the following reaction parameters; temperature; amount of catalyst, substrate and oxidant; presence of acetic acid; effect of counter-ion associate
Publicado em: 1991
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17. Oxidação de cicloexano pelo sistema GIF : sobre-oxidação e influencia dos ligantes
In earlier research, it had not been possible to close the mass balance for cyclohexane oxidation by the Gif system. lnitially we quantified the losses of cyclohexane by evaporation and were able to improve the mass balances to 97,2% at 20°C and to 99,6% a 80°C. ln order to explain the remaining differences we looked for possible overoxidation and/or coupl
Publicado em: 1991
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18. Estudos de R. M. N. de 1H e de 13C de cidoescanonas a-heterossubstituidas
The aim of the present work has been the study of the conformational equilibrium of some a-monosubstituted cyclohexanones (2 to 11) by Hydrogen-1 and Carbon-13 nuclear magnetic resonance spectroscopy, and the effect of the several substituents in the Carbon-13 chemical shifts of the carbon atoms of the cyclohexanone ring has also been circumstantially invest
Publicado em: 1991
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19. Simultaneous Identification of Two Cyclohexanone Oxidation Genes from an Environmental Brevibacterium Isolate Using mRNA Differential Display
The technique of mRNA differential display was used to identify simultaneously two metabolic genes involved in the degradation of cyclohexanone in a new halotolerant Brevibacterium environmental isolate. In a strategy based only on the knowledge that cyclohexanone oxidation was inducible in this strain, the mRNA population of cells exposed to cyclohexanone w
American Society for Microbiology.
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20. mRNA Differential Display in a Microbial Enrichment Culture: Simultaneous Identification of Three Cyclohexanone Monooxygenases from Three Species
mRNA differential display has been used to identify cyclohexanone oxidation genes in a mixed microbial community derived from a wastewater bioreactor. Thirteen DNA fragments randomly amplified from the total RNA of an enrichment subculture exposed to cyclohexanone corresponded to genes predicted to be involved in the degradation of cyclohexanone. Nine of the
American Society for Microbiology.
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21. Temporal epileptic seizures and occupational exposure to solvents.
Long term exposure to organic solvents is usually not considered as a possible cause of chronic epileptic seizures. A case that shows a remarkable coincidence between exposure to organic solvents and occurrence of epileptic seizures is reported. The man was a 58 year old sign writer with lifelong exposure to a mixture of organic solvents (mainly cyclohexanon
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22. Comparative Study of the Ability of Three Xanthobacter Species To Metabolize Cycloalkanes
The ability of three species of Xanthobacter to metabolize cyclohexane and its derivatives has been compared. Xanthobacter flavus was unable to utilize any of the cycloalkanes under investigation. X. autotrophicus was unable to utilize cyclohexane but was able to grow with a limited range of substituted cycloalkanes, including cyclohexanol and cyclohexanone.
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23. Acinetobacter cyclohexanone monooxygenase: gene cloning and sequence determination.
The gene coding for cyclohexanone monooxygenase from Acinetobacter sp. strain NCIB 9871 was isolated by immunological screening methods. We located and determined the nucleotide sequence of the gene. The structural gene is 1,626 nucleotides long and codes for a polypeptide of 542 amino acids; 389 nucleotides 5' and 108 nucleotides 3' of the coding region are
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24. Identification of a Transcriptional Activator (ChnR) and a 6-Oxohexanoate Dehydrogenase (ChnE) in the Cyclohexanol Catabolic Pathway in Acinetobacter sp. Strain NCIMB 9871 and Localization of the Genes That Encode Them†
We identified chnR, a gene encoding an AraC-XylS type of transcriptional activator that regulates the expression of chnB, the structural gene for cyclohexanone monooxygenase (CHMO) in Acinetobacter sp. strain NCIMB 9871. The gene sequence of chnE, which encodes an NADP+-linked 6-oxohexanoate dehydrogenase, the enzyme catalyzing the fifth step of cyclohexanol
American Society for Microbiology.