3071-34-9Relevant articles and documents
External Oxidant-Dependent Reactivity Switch in Copper-Mediated Intramolecular Carboamination of Alkynes: Access to a Different Class of Fluorescent Ionic Nitrogen-Doped Polycyclic Aromatic Hydrocarbons
Shaikh, Aslam C.,Banerjee, Somsuvra,Mule, Ravindra D.,Bera, Saibal,Patil, Nitin T.
, p. 4120 - 4130 (2019)
An interesting case of external oxidant-controlled reactivity switch leading to a divergent set of ionic nitrogen-doped polycyclic aromatic hydrocarbons (N-doped PAHs), is presented here, which is quite unrecognized in copper-mediated reactions. In the current scenario, from the same pyridino-alkyne substrates, the use of the external oxidant PhI(OAc)2, in combination with Cu(OTf)2, gave N-doped spiro-PAHs via a dearomative 1,2-carboamination process; whereas, without the use of oxidant, an alkyne/azadiene [4 + 2]-cycloaddition cascade occurred to exclusively afford ionic N-doped PAHs. These newly synthesized N-doped PAHs further exhibit tunable emissions, as well as excellent quantum efficiencies.
Secondary phosphine oxide-triggered selective oxygenation of a benzyl ligand on palladium
Oka, Sayaka,Shigehiro, Yuma,Kataoka, Yasutaka,Ura, Yasuyuki
supporting information, p. 12977 - 12980 (2020/11/05)
The oxygenation of a benzyl ligand in [PdBnCl(cod)] was dramatically accelerated by using secondary phosphine oxides (SPOs), selectively affording either BnOOH or BnOH, depending on the concentration of O2. The SPOs coordinate to palladium in the form of phosphinous acids, operating as Br?nsted acids to facilitate further reaction with O2. This journal is
Indium-Mediated Synthesis of Benzylic Hydroperoxides
Hou, Yuxuan,Hu, Jinjin,Xu, Ruigang,Pan, Shulei,Zeng, Xiaofei,Zhong, Guofu
supporting information, p. 4428 - 4432 (2019/06/17)
An indium(0)-metal-mediated efficient synthesis of benzylic hydroperoxides is described. The reaction proceeds efficiently with a broad range of benzyl bromides under aerobic conditions at room temperature to afford benzyl hydroperoxides in good to excellent yields. In addition, the tandem hydroperoxidation-Michael addition of (E)-1-(bromomethyl)-2-(2-nitrovinyl)benzene was also demonstrated.
Oxygenation of a benzyl ligand in SNS-palladium complexes with O2: Acceleration by anions or Br?nsted acids
Shimokawa, Reina,Kawada, Yumi,Hayashi, Miki,Kataoka, Yasutaka,Ura, Yasuyuki
supporting information, p. 16112 - 16116 (2016/10/31)
A cationic SNS-benzylpalladium complex was reacted with O2 under several conditions, affording oxygenated compounds derived from the benzyl ligand. The addition of n-Bu4NX remarkably accelerated the oxygenation, furnishing benzaldehyde as a main organic product and dinuclear complexes; in contrast, HX also promoted the oxygenation, but mainly produced benzyl hydroperoxide and mononuclear complexes.
Synthesis of alkyl hydroperoxides via alkylation of gem -dihydroperoxides
Kyasa, Shivakumar,Puffer, Benjamin W.,Dussault, Patrick H.
, p. 3452 - 3456 (2013/06/26)
2-Fold alkylation of 1,1-dihydroperoxides, followed by hydrolysis of the resulting bisperoxyacetals, provides a convenient method for synthesis of primary and secondary alkyl hydroperoxides.
Method for oxidizing hydrocarbons
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, (2008/06/13)
The invention relates to a method for oxidizing substrates such as hydrocarbons, waxes or soot. The method involves the use of a compound of formula (I) in which: R1 and R2 represent H, an aliphatic or aromatic alkoxy radical, carboxyl radical, alkoxycarbonyl radical or hydrocarbon radical, each having 1 to 20 hydrocarbon atoms, SO3H, NH2, OH, F, Cl, Br, I and/or NO2, whereby R1 and R2 designate identical or different radicals or R1 and R2 can be linked to one another via a covalent bonding; Q1 and Q2 represent C, CH, N, CR5, each being the same or different; X and Z represent C, S, CH2, each being the same or different; Y represents O and OH; k=0, 1, 2; l=0, 1, 2; m=1 to 3, and; R5 represents one of the meanings of R1. Said compound is used as a catalyst in the presence of a radical initiator, whereby the molar ratio of the catalyst to the hydrocarbon is less than 10 mol %. Peroxy compounds or azo compounds can be used as the radical initiator. Preferred substrates are aliphatic or aromatic hydrocarbons.
The oxidation of ethylbenzene and other alkylaromatics by dioxygen catalysed by iron(III) tetrakis(pentafluorophenyl)porphyrin and related iron porphyrins
Evans, Steven,Smith, John R. Lindsay
, p. 1541 - 1551 (2007/10/03)
The oxidation of ethylbenzene with dioxygen catalysed by iron(III) porphyrins in a solvent free system has been studied over the temperature range 30-110°C. The time dependence of the formation of the three main products, 1-phenylethanol, acetophenone and 1-phenylethyl hydroperoxide, and the fate of the iron porphyrin are interpreted in terms of a free radical autoxidation mechanism. The yields of the oxidation products are determined by the rate of reaction and by the lifetime of the catalyst. Catalyst degradation is shown to involve reaction of the porphyrin ligand with 1-phenylethoxyl and 1-phenylethylperoxyl radicals. The disadvantages of increased induction periods and longer reaction times of the oxidations observed at lower reaction temperatures are counter balanced by increased catalyst turnovers. Less extensive studies on the oxidations of toluene, cumene, (2-methylpropyl)-benzene and tert-butylbenzene support the overall mechanism proposed for ethylbenzene. A comparative study using the catalysts iron(III) 2,3,7,8,12,13,17,18-octachloro-5,10,15,20-tetrakis-(2,6-dichlorophenyl)porphyrin and iron(III) tetrakis(pentafluorophenyl)porphyrin and five of its derivatives reveals that halogenation of the β-pyrrole positions markedly increases the activity of the catalysts but not the stability of the porphyrin towards degradation. The highest yields were obtained with the μ-oxodimer of iron(III) tetrakis(pentafluorophenyl)porphyrin and iron(III) tetrakis(4-dimethylamino-2,3,5,6-tetrafluorophenyl)-porphyrin.
Mikroporoese Mischoxide - Katalysatoren mit einstellbarer Oberflaechenpolaritaet
Klein, Stephan,Maier, Wilhelm F.
, p. 2376 - 2379 (2007/10/03)
Keywords: Katalyse; Mischoxide; Oxidationen; Siliciumverbindungen; Titanverbindungen
Methyltrioxorhenium catalyzed oxidation of saturated and aromatic hydrocarbons by H2O2 in air
Schuchardt, Ulf,Manddli, Dalmo,Shul'Pin, Georgiy B.
, p. 6487 - 6490 (2007/10/03)
Alkanes (cyclohexane, cyclooctane, n-heptane) and aromatic compounds (benzene, toluene, and ethylbenzene) are oxidized by anhydrous H2O2 in MeCN in air in the presence of catalytic amounts of MTO. The reaction in accelerated by addition of pyrazine-2-carboxylic acid. Alkanes give alkyl hydroperoxides as main products, as well as alcohols and ketones. Arenes yield predominantly phenols.
A Kinetic and Mechanistic Study of the Self-Reaction and Reaction with H2O of the Benzylperoxy Radical
Noziere, Barbara,Lesclaux, Robert,Hurley, Michael D.,Dearth, Mark A.,Wallington, Timothy J.
, p. 2864 - 2873 (2007/10/02)
The kinetics and mechanism of the reactions C6H5CH2O2 + C6H5CH2O2 -> 2C6H5CH2O + O2 (3a), C6H5CH2O2 + C6H5CH2O2 -> C6H5CHO + C6H5CH2OH + O2 (3b), and C6H5CH2O2 + HO2 -> C6H5CH2OOH + O2 (4) have been investigated using two complementary techniques: flash photolysis/UV absorption for kinetic measurements and continuous photolysis/FTIR spectroscopy for end-product analyses and branching ratio determinations.The reaction of chlorine atoms with toluene was found to yield benzyl radicals exclusively and was used to generate benzylperoxy radicals in excess oxygen.During this study, relative reaction rate constants of chlorine atoms with compounds related to those involved in the reaction mechanism have been measured at room temperature: k(Cl+toluene) = (6.1 +/- 0.2)E-11, k(Cl+benzaldehyde) = (9.6 +/- 0.4)E-11, k(Cl+benzyl chloride) = (9.7 +/- 0.6)E-12, k(Cl+benzyl alcohol) = (9.3 +/- 0.5)E-11, k(Cl+benzene) 3 molecule-1 s-1.The products identified following the self-reaction 3 were benzaldehyde, benzyl alcohol, and benzyl hydroperoxide.The latter is the product of the reaction of C6H5CH2O2 with HO2.The yield of products allowed us to determine the branching ratio α = k3a/k3 = 0.4.The UV absorption spectrum of the benzylperoxy radical was determined from 220 to 300 nm.It was similar to those of alkylperoxy radicals, with a maximum cross section at 245 nm of 6.8E-18 cm2 molecule-1.Kinetic data were obtained from the detailed simulation of experimental decay traces recorded at 250 nm over the temperature range 273-450 K.The resulting rate expression are k3 = (2.75 +/- 0.15)E-14 exp cm3 molecule-1 a-1 and k4 = (3.75 +/- 0.32)E-13 exp3 molecule-1 s-1 (errors = 1?).The UV absorption traces in the flash-photolysis kinetic study were well accounted for by the identified products in the FTIR study, thus providing good confidence in the results.However, about 20percent of the products have remained unidentified.Some uncertainties persist in the reaction mechanism leading us to assign a fairly large uncertainty of about 50percent to the rate constants k3 and k4 over the whole temperature range.This work shows that the aromatic substituent does not provide any specificity in the reactivity of peroxy radicals and confirms that large radicals tend to react faster with HO2 than generally assumed in current atmospheric models.
