89482-40-6Relevant articles and documents
Hydrogen abstraction from unactivated hydrocarbons using a photochemically excited isoindoline nitroxide
Bottle, Steven E.,Chand, Ugesh,Micallef, Aaron S.
, p. 857 - 858 (1997)
The photochemical! y excited nitroxide, 1,1,3,3-tetramethylisoindolin-2-yloxyl (1*), abstracts primary, secondary or tertiary hydrogens from unactivated hydrocarbons including cyclohexane, isobutane and n-butane. The resultant carbon-centred radicals are rapidly and efficiently trapped by ground state nitroxide. Hydrogen abstraction from methane may also occur, but is masked by secondary photochemical reactions.
Study of alkyl radicals fragmentation from 2-alkyl-2-propoxyl radicals
Nakamura, Tomoyuki,Watanabe, Yasumasa,Suyama, Shuji,Tezuka, Hiroshi
, p. 1364 - 1369 (2007/10/03)
The reaction of a series of 2-alkyl-2-propoxyl radicals 2 in cumene has been studied. Alkoxyl radicals 2 were generated from the thermolysis of the corresponding tert-alkyl peroxypivalates, and underwent several modes of unimolecular reactions, that is, β-scission to give methyl radical, β-scission to give alkyl radicals and 1,5-H shift, which competed with hydrogen abstraction from cumene. The ratios of the rate constant for alkyl radicals elimination to that for methyl radical elimination, kβ(R)/kβ(Me), were determined by using the radical trapping method employing TEMIO as the scavenger. The logarithm of the relative rate was satisfactorily correlated with the heat of formation of the leaving alkyl radicals containing the steric parameters of neopentyl radical 2d. Then the plot of ln [kβ(R)/kβ(Me)] vs. the SOMO energies of the corresponding alkyl radicals showed a linear relationship with a slope of -7.6 eV-1, which is comparable to that of formolysis of alkyl bromides. The mechanism involving a fairly polar transition state of the alkyl radicals fragmentation from tert-alkoxyl radicals 2 is discussed in terms of the MO diagrams and the solvent effects.
Reactions of tert-Butoxyl Radicals with Cyclic Ethers Studied by the Radical Trapping Technique
Busfield, W. Ken,Grice, I. Darren,Jenkins, Ian D.
, p. 1079 - 1086 (2007/10/02)
The pattern and relative rate of abstraction reactions of tert-butoxyl radicals with fourteen cyclic alkanes and cyclic ethers have been investigated by the aminoxyl radical trapping technique.Oxygen α to C-H strongly enhances abstraction, but β to C-H generally retards abstraction.The rate of abstraction of hydrogens α to oxygen in cyclic ethers was found to decrease with ring size in the order 5 > 7 >> 6 > 4.The results are discussed in terms of ring size, abstraction position relative to ethereal oxygen atoms in the ring and aliphatic substitution.Factors such as polarity, torsional strain, hybridisation of the oxygen (whether sp2 or sp3) and the anomeric effect are considered.