2406-25-9Relevant academic research and scientific papers
Trans-1,2-Disiloxybenzocyclobutene, an adequate partner for the auto-oxidation: EPR/spin trapping and theoretical studies
Drujon, Jean,Rahmani, Raphael,Heran, Virginie,Blanc, Romain,Carissan, Yannick,Tuccio, Beatrice,Commeiras, Laurent,Parrain, Jean-Luc
, p. 7513 - 7520 (2014)
The auto-oxidation of trans-1,2-disiloxybenzocyclobutene 1 was found to be very efficient, giving endo-peroxide 7 in quantitative yield. Each step of the mechanism of spin-forbidden addition of triplet oxygen O2( 3Σg) was
Intramolecular Hydrogen Atom Transfer in Aminyl Radical at Room Temperature with Large Kinetic Isotope Effect
Wang, Ying,Olankitwanit, Arnon,Rajca, Suchada,Rajca, Andrzej
, p. 7144 - 7147 (2017)
We report a large kinetic isotope effect at 298 K, kH/kD ≈ 150, associated with an intramolecular 1,5-hydrogen atom transfer (1,5-HAT) in the decay of a PEGylated carbazyl (aminyl) radical in solution. The experimental observations surprisingly combine the hallmarks of tunneling, including large KIEs and unusual activation parameters, with linear Arrhenius and Eyring plots over an exceptionally wide temperature range of 116 K.
Kinetic model of radical reaction in plastic crystals
Morosov,Shabatina,Batyuk,Sergeev
, p. 117 - 123 (1994)
The kinetic features of diffusion-depended model process of photoinduced nitroxide formation from 2-methyl-2-nitrosopropane in a number of plastic crystals (PC: cyclohexane, cyclohexanol, cyclohexanon, cyclopentanon, 1,1,1-trichlorethane, tert-butylchloride, tert-butylamine, tert-butanol, benzene have been studied by ESR. The kinetic model that relates the nitroxide formation quantum yield with parameters of Lennard - Jones' potentials and thermodynamic properties of PC is proposed.
Photoactivatable platinum anticancer complex can generate tryptophan radicals
Vallotto, Claudio,Shaili, Evyenia,Shi, Huayun,Butler, Jennifer S.,Wedge, Christopher J.,Newton, Mark E.,Sadler, Peter J.
, p. 13845 - 13848 (2018)
l-Tryptophan (Trp), melatonin (MLT) and the Trp-peptide pentagastrin quenched the formation of azidyl radicals generated on irradiation of the anticancer complex trans,trans,trans-[Pt(pyridine)2(N3)2(OH)2] with visible light, giving rise to C3-centred indole radicals which were characterized for Trp and MLT using an EPR spin-trap; indole, together with azidyl and hydroxyl radicals, have potential roles in a multitargeting mechanism of action against resistant cancers.
Mechanism of SmI2 Reduction of 5-Bromo-6-oxo-6-phenylhexyl Methanesulfonate Studied by Spin Trapping with 2-Methyl-2-nitrosopropane
Aretz, Christopher D.,McPeak, Joseph E.,Eaton, Gareth R.,Eaton, Sandra S.,Cowen, Bryan J.
, p. 10688 - 10692 (2018)
The radical formed by reduction of 5-bromo-6-oxo-6-phenylhexyl methanesulfonate, an α-bromoketone, with SmI2 was spin trapped with 2-methyl-2-nitrosopropane. Electron paramagnetic resonance spectra of the spin adduct and the adduct formed in the analogous reaction with selectively deuterated substrate identify the radical intermediate in this SmI2 reduction as a carbon-centered radical. This result supports the proposal that the formation of reactive Sm-enolates arises from reduction of the carbon-bromine bond rather than a ketyl radical anion.
Reactions of Ruthenium Formyl and Related Complexes with Nitroxide Spin Traps
Smith, Garry,Sutcliffe, Leslie H.,Cole-Hamilton, David J.
, p. 1209 - 1214 (1984)
Reactions of the complexes trans- (dppe=Ph2PCH2CH2PPh2), cis- (dppm=Ph2PCH2PPh2), or trans- with ButNO give But2NO. and trans-tNO)(CO)(P-P)2>.+ (M=Ru, P-P=dppe or dppm; M=Os, P-P=dppe), the structures of which have been elucidated by e.s.r. and labelling (13C, 2H) studies. cis- or trans-+ gives only But2NO., whilst trans-2+ gives a mixture of trans-tNO)PPh2>>.2+ and a radical with the trap bound to a carbonyl carbon atom.The decomposition products of cis-+ gave a radical with the trap bound to the back-bone carbon atom of a chelating dppm ligand, whilst dppe and dppm both give radicals where the ButNO group is bound to a phosphorus atom.The mechanisms of some of these reactions are discussed.
NO spin trapping and EPR studies on the photochemistry of aliphatic aldehydes
Wang, Fan,Lei, Liandi,Wu, Longmin
, p. 156 - 165 (2005)
Radicals, such as acyl, hydrated acyl, alkyl and ketyl radicals, from aliphatic aldehyde photochemistry were detected by NO spin trapping and EPR techniques. Deuterium effects on EPR spectra and the generation of radicals by 2-amido-2-propyl radical attack on substrate molecules in aqueous solution via hydrogen-atom abstraction were applied to identify radicals produced photochemically from aldehydes. Aliphatic aldehydes used in the present investigation were formaldehyde, acetaldehyde, acetaldehyde-d4, propionaldehyde, isobutyraldehyde, isopentanal and tert-pentanal. Possible reaction mechanisms are suggested. Copyright
A Free-Radical-Promoted Site-Specific Cross-Dehydrogenative-Coupling of N-Heterocycles with Fluorinated Alcohols
Xu, Zhengbao,Hang, Zhaojia,Chai, Li,Liu, Zhong-Quan
supporting information, p. 4662 - 4665 (2016/09/28)
A C-C formation of an electron-rich N-heterocycle with fluorinated alcohol is developed. Through this radical-triggered cross-dehydrogenative coupling strategy, a wide range of useful building blocks such as C3 hydroxyfluoroalkylated indoles and pyrroles can be site-specifically synthesized. Mechanistic studies indicate a single-electron-transfer initiated radical cycle would be involved.
An EPR study of the radical addition to 3-nitropentan-2-one as an archetype of α-carbonylnitroalkanes
Campredon, Mylene,Alberti, Angelo
, p. 289 - 297 (2014/06/09)
Carbon, silicon, germanium, tin and lead-centered radicals were reacted with 3-nitropentan-2-one and 3-nitropentan-2-ol inside the cavity of an electron paramagnetic resonance spectrometer. In all cases, selective addition to the nitrogroup was observed with detection of the corresponding oxynitroxide radicals. In the case of the carbonyl substrate, alkyl acyl nitroxides were also detected because of α-photocleavage. The oxynitroxides decayed with a first order kinetics via fragmentation of the carbon-nitrogen bond (denitration). Unexpectedly, the activation parameters were fairly similar to those previously reported for the corresponding tert-butyl oxynitroxides and almost independent from the presence of a carbonyl or a hydroxyl group on the carbon adjacent to the one bearing the nitrogroup. Copyright
The photoreactions of simple amides with NO. Gaining insight into radical bio-damages through an EPR case study
Alberti, Angelo,Grossi, Loris,MacCiantelli, Dante
supporting information; experimental part, p. 2662 - 2670 (2012/05/04)
Eight simple amides have been subjected to UV irradiation in the presence of either MNP or NO. In all cases radical species were generated: these were detected by means of EPR spectroscopy in the form of different nitroxides resulting from the trapping of the primary radicals. NO acted as a double spin trap, scavenging a radical to afford a diamagnetic nitroso derivative that in turn acted as trap towards another radical unit. As amido-groups are present in components of skin tissue and may be present in many therapeutic or cosmetic products used as skin sunscreen, and NO is a ubiquitous endogenous reactive species, the nitroxides detected in the present studies might participate in radical processes triggered by sun exposure and resulting in damages, even severe, of biological tissues.
