4198-93-0Relevant academic research and scientific papers
Interconversion of Carbocations, Free Radicals and Carbanions in Nitroxide Solutions
Singh, Hari,Tedder, John M.
, p. 70 - 71 (1981)
Both triphenylmethyl anions and cations are converted into triphenylmethyl radicals when dissolved in solutions containing di-t-butyl nitroxide; when oxygen is admitted both solutions yield triphenylmethylperoxyl radicals, but in the carbocation system the nitroxide is decomposed while in the carbanion system it is regenerated.
Generation and Confinement of Long-Lived N-Oxyl Radical and Its Photocatalysis
Zhang, Chaofeng,Huang, Zhipeng,Lu, Jianmin,Luo, Nengchao,Wang, Feng
supporting information, p. 2032 - 2035 (2018/02/19)
Generation of controllable carbon radical under the assistance of N-oxyl radical is an efficient method for the activation of C-H bonds in hydrocarbons. We herein report that irradiation of α-Fe2O3 and N-hydroxyphthalimide (NHPI) under 455 nm light generates phthalimide-N-oxyl radical (PINO), which after being formed by oxidation with holes, is confined on α-Fe2O3 surface. The half-life time of the confined radical reaches 22 s as measured by in situ electron paramagnetic resonance (EPR) after the light being turned off. This allows the long-lived N-oxyl radical to abstract the H from C-H bond to form a carbon radical that reacts with molecular oxygen to form R3C-OO· species, decomposition of which leads to oxygenated products.
PROCESS FOR OPTICALLY ACTIVE SULFOXIDE COMPOUNDS
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Page/Page column 20, (2009/06/27)
The present invention discloses novel processes for preparing optically active sulphoxide compounds of formula I by asymmetric oxidation of prochiral sulphide compounds of Formula II. More particularly, the invention discloses processes for preparation of optically active proton pump Inhibitors (PPIs) or their optically active precursor (=intermediate) compounds (Formula I) that can be converted into pharmaceutically useful PPIs.
System vanadium alkoxy compound-tert-butyl hydroperoxide-oxidant of hydrocarbon C-H bonds
Stepovik,Gulenova,Tishkina,Cherkasov
, p. 1254 - 1262 (2008/03/12)
Vanadium alkoxy compounds [(t-BuO)4V, (t-BuO)3VO] react with tert-butyl hydroperoxide (C6H6, 20°C) to liberate oxygen, partly in the singlet form, and to form alkoxyl and peroxyl radicals via the intermediacy of vanadium peroxides and trioxide. These systems are capable of oxidizing hydrocarbon C-H bonds. The process is radical in nature and involves formation of carbon-centered radicals and their reaction with oxygen generated in the systems. Vanadium-containing peroxides, too, take part in the oxidation reaction.
The radical chemistry of t-butyl hydroperoxide (TBHP) - Part 3 - Further studies on hydrocarbon activation
Barton, Derek H. R.,Le Gloahec, Valerie N.
, p. 15457 - 15468 (2007/10/03)
Further aspects of the chemistry of TBHP in the presence of Fe(II) and Fe(III) species have been investigated. Now all the results previously reported with TBHP can be understood in terms of radical chemistry. Oxidation states of iron higher than Fe(III) are not involved.
Oxidation of Alkylarenes by the Aluminum Tri-tert-butoxide-tert-Butyl Hydroperoxide System
Stepovik,Dodonov,Zaburdaeva
, p. 111 - 115 (2007/10/03)
Oxidation of several alkylarenes containing primary, secondary, and tertiary radicals (cumene, 1,1-diphenylethane, triphenylmethane, and 1,1-diphenylpropane) by the aluminum tri-tert-butoxide-tert-butyl hydroperoxide system was studied. Oxidation of cumene, 1,1-diphenylethane, and triphenylmethane proceeds through the formation of tertiary hydroperoxides due to dimerization of hydroperoxy and carbon-centered radicals. Reaction of 1,1-diphenylpropane with the oxidation system occurs through the methylene group and is accompanied by cleavage of the carbon-carbon bond of alkylarene.
THE SELECTIVE FUNCTIONALIZATION OF SATURATED HYDROCARBONS. PART 28. THE ACTIVATION OF BENZYLIC METHYLENE GROUPS UNDER GOAGGIV AND GOAGGV CONDITIONS
Barton, Derek H. R.,Wang, Tie-Lin
, p. 1011 - 1032 (2007/10/02)
Under GoAggIV and GoAggV conditions, cyclohexadienes were oxidized to give aromatic products instead of ketones and alcohols.At the same time, anthracene was oxidized to give anthraquinone.Under GoAggIV and GoAggV conditions, xanthene, fluorene and diphenylmethane were oxidized to give the corresponding xanthone, fluorenone and benzophenone following two possible pathways: a) alkane to alkyl t-butylperoxide to ketone, and b) alkane to ketone, in which alkyl hydroperoxide, derived from oxygen, may be the reaction intermediate.Xanthyl azide was formed when sodium azide was added to the reaction mixture of xanthene under GoAggIV and GoAggV conditions.The reaction of triphenylmethane under GoAggV conditions gave triphenylmethyl t-butyl peroxide as the major product and hydroperoxide as the minor product.When TEMPO was added, triphenylmethyl hydroperoxide was the only product.
Mechanism of asymmetric epoxidation. 1. Kinetics
Woodard, Scott S.,Finn,Sharpless, K. Barry
, p. 106 - 113 (2007/10/02)
The rate of titanium-tartrate-catalyzed asymmetric epoxidation of allylic alcohols is shown to be first order in substrate and oxidant, and inverse second order in inhibitor alcohol, under pseudo-first-order conditions in catalyst. The rate is slowed by substitution of electron-withdrawing substituents on the olefin and varies slightly with solvent, CH2Cl2 being the solvent of choice. Asymmetric induction suffers when the size of the alkyl hydroperoxide is reduced. Kinetic resolution of secondary allylic alcohols is shown to be sensitive to the size of the tartrate ester group and insensitive to the steric nature of inhibitor alcohol. Most importantly, the species containing equimolar amounts of Ti and tartrate is shown to be the most active catalyst in the reaction mixture, mediating reaction at much faster rates than titanium tetraalkoxide alone.
Homosolvolysis
Scott, Alan C.,Tedder, John M.,Walton, John C.,Mhatre, Sushila
, p. 260 - 266 (2007/10/02)
Nitroxides, when used as solvents, promote the homolysis of a variety of weak bonds.Strong chemical evidence for the formation of free radicals is confirmed by e.s.r. studies in which the formation of free radicals has been monitored.This fission of single bonds of solute molecules dissolved in solvents with unpaired electrons is called homosolvolysis, in contrast to the common bond fission observed in polar solvents which is called heterosolvolysis.
