27064-03-5Relevant academic research and scientific papers
Selective oxidation of hydrocarbons under air using recoverable silver ferrite-graphene (AgFeO2-G) nanocomposite: A good catalyst for green chemistry
Hosseini, Seyed Majid,Hosseini-Monfared, Hassan,Abbasi, Vahideh,Khoshroo, Mohammad Reza
, p. 72 - 79 (2016/04/10)
The selective oxidation of hydrocarbons is a main academic and industrial research challenge. A lot of researches have been done about this issue, but till now relatively little attention has been paid to graphene-complex oxide nanocomposites. Herein, we report our studies on a new catalyst. Silver ferrite-graphene (AgFeO2-G) as a separable nanocomposite from the reaction solution, was used as an effective oxidizing agent for the oxidation of various hydrocarbons (1- decene, cyclohexene, cis-cycloctene, cyclohexane, cyclooctane etc.) under mild conditions (55 °C, 8 h) with high conversion and selectivity using air, that is proper for 'green' chemistry. Metal or metal oxide nanoparticles assembled on graphene sheets revealed high electrocatalytic activity. Indeed, AgFeO2 with graphene due to low band gap and graphene oxide with large amounts of oxygen-containing groups, provide facility catalytic activity of catalyst-supported system. We also found that, with this catalyst, selective oxidation could be achieved without the need for the addition of solvent, which is appropriate in particular for 'green' chemistry. The catalysts showed little deactivation and maintained their conversion and selectivity levels duration of the measurements.
Synthesis and singlet oxygen reactivity of 1,2-diaryloxyethenes and selected sulfur and nitrogen analogs
Nkepang, Gregory,Pogula, Praveen K.,Bio, Moses,You, Youngjae
experimental part, p. 753 - 759 (2012/09/05)
1,2-Diaryloxyethene has recently been proposed as a linker in singlet oxygen-mediated drug release. Even though 1,2-diaryloxyethenes look very simple, their synthesis was not an easy task. Previous methods are limited to symmetric molecules, lengthy step and low yield. We report on a facile synthetic method not only for 1,2-diaryloxyethenes but also their sulfur and nitrogen analogs in yields ranging from 40 to 90% with more than 90% purity at the vinylation reaction. Most recently, light-controlled drug release systems were proposed, where singlet oxygen generated from low energy light and a photosensitizer cleaves electron-rich alkenes, e.g. 1,2-diaryloxyethene. However, the synthesis of 1,2-diaryloxyethene was not well established. Herein, we report a facile synthesis of 1,2-diaryloxyethenes and its sulfur and nitrogen analogs. Model compounds were prepared in four steps from 4-phenylphenol via Ullman-type coupling reaction.
Low energy light-triggered oxidative cleavage of olefins
Murthy, Rajesh S.,Bio, Moses,You, Youngjae
scheme or table, p. 1041 - 1044 (2009/05/27)
A series of substituted olefins were tested for their reactivity with singlet oxygen as a singlet oxygen-mediated cleavable linker. Low intensity light of 200 mW/cm2 was irradiated to the solution of an olefin and 5,10,15-triphenyl-20-(4-hydroxyphenyl)-21H,23H-porphyrin under atmospheric condition. Among the tested olefins, 1,2-cis-diphenoxyethylene reacted fast with singlet oxygen, >80% within 15 min yielding a stoichiometric conversion to aldehyde product without any side reactions.
Chemoselective oxidation of primary alcohols to aldehydes with Gluconobacter oxydans
Villa, Raffaella,Romano, Andrea,Gandolfi, Raffaella,Sinisterra Gago, José V.,Molinari, Francesco
, p. 6059 - 6061 (2007/10/03)
The production of aliphatic and aromatic aldehydes by oxidation of primary alcohols was achieved with Gluconobacter oxydans DSM 2343. The biotransformation was optimised studying the oxidation of 2-phenyl-1-ethanol to 2-phenylacetaldehyde. A high molar conversion (95% chromatographic conversion, 83% of isolated yield) was obtained using cells grown on glycerol as the main carbon source and directly used in the cultural medium after 24 h at 28°C, pH 4.5 and 5 g L-1 substrate concentration. The conversion of structurally different primary alcohols was performed under these conditions allowing the chemoselective production of aldehydes, sometimes with very good yields.
Thiophilic addition of organolithiums to trithiocarbonate oxides (sulfines). Synthesis of β-oxoketene dithioacetals, 1,4-dicarbonyl compounds, and allyl sulfoxides
Leriverend, Catherine,Metzner, Patrick,Capperucci, Antonella,Degl'Innocenti, Alessandro
, p. 1323 - 1342 (2007/10/03)
Reaction of trithiocarbonates with meta-chloroperoxybenzoic acid in CH2Cl2 at 0°C affords the corresponding S-oxides. These sulfines are relatively stable comppounds which can be purified by chromatography. They react readily with organolithiums in THF at -78°C in a thiophilic manner to give carbanions which are stabilized by three sulfur groups. Hydrolysis affords trithioorthoester oxides. The thermal behaviour of these hindered products has been investigated and new rearrangenrent processes have been evidenced. The former carbanions are soft nucleophiles: 1,4-addition of these intermediates to α-enones was achieved selectively to lead to β-oxo ketenedithioacetals, which are easily transformed into 4-oxoalkanethioates. This 'Umpolung' route allows the formal use of the (alkylthio)carbonyl anion. A thiophilic addition was also observed with allylsilanes in the presence of n-Bu4NF furnishing allyl sulfoxides.
Selectivity towards hydrodehalogenation and dehalo-coupling in the reduction of trichloromethyl derivatives with iron(II) chloride
Folli, Ugo,Goldoni, Francesca,Iarossi, Dario,Sbardellati, Silvia,Taddei, Ferdinando
, p. 1017 - 1020 (2007/10/02)
The reductive electron transfer (ET) induced on a series of RCCl3 derivatives by iron(II) chloride has been studied.The main reaction products are the homocoupling dimer, RCCl2-CCl2R, and the H/Cl substitution derivative, RCHCl2, and the majority of the compounds examined exhibit a highly selective tendency to form just one of these products.As a general rule, the RCHCl2 compound is the main product when the R group contains substituents which make further reduction of the radical to the carbanion easier and behave as ligands towards the iron(II) ion.In the other cases, the dimer RCCl2-CCl2R is the main product.A few exceptions are found, and these are discussed in view of the possible effects of the R moiety on the different possible routes for the reaction products.The presence of unsaturated derivatives, RCCl=CClR (E/Z mixture), was observed in the case of the reactions where the homocoupling product was also obtained and is ascribed, on the basis of experimental evidence, to a dehalogenation mechanism of the dimer RCCl2-CCl2R assisted by the iron(II) ion.
SPIROADAMANTYL STABILIZATION OF SULFUR-SUBSTITUTED 1,2-DIOXETANES
Adam, Waldemar,Arias, Luis A.,Scheutzow, Dieter
, p. 2835 - 2836 (2007/10/02)
With the help of spiroadamantyl substitution, the first sulfur-substituted 1,2-dioxetanes 9 and 10, respectively derived from thiophenylmethyleneadamantane (7) and 2-adamantylidene-1,3-dithian (8) were prepared via singlet oxygenation and detected by NMR.
The Addition of Carbanions to the Carbonyl Group in the Gas Phase
Bartmess, J. E.,Hays, R. L.,Caldwell, G.
, p. 1338 - 1344 (2007/10/02)
The reaction of a variety of carbanions with esters in the gas phase proceeds by an addition-elimination-deprotonation mechanism, similar to that for the Claisen condensation in solution.The observed ion-molecule reactivities are analyzed in terms of a triple-minimum reaction coordinate.The thermochemistry of the various barriers along this coordinate explains the occurrence or absence of the condensation product.The effect of solvation on the reaction coordinate and the nature of the reactants is discussed.
