75354-09-5Relevant academic research and scientific papers
New Syntheses of Mixed Peroxides under Gif-Barton Oxidation of Alkylbenzenes, Conjugated Alkenes and Alkanes; a Free-radical Mechanism
Minisci, Francesco,Fontana, Francesca,Araneo, Silvia,Recupero, Francesco
, p. 1823 - 1824 (2007/10/02)
Syntheses of mixed peroxides are performed under Gif oxidation of alkylaromatics, electron-rich conjugated alkenes (styrene, α-methylstyrene) or cyclohexane and acrylonitrile; chemical and kinetic evidence support a free-radical redox chain mechanism.
Polar Substituent Effects in Additions of Alkyl Radicals to Alkenes
Giese, Bernd,Meixner, Juergen
, p. 2138 - 2145 (2007/10/02)
Reduction of cyclohexylmercuric salts (7) with NaBH4 yields cyclohexyl radicals (8).Their rel. rates of addition to substituted styrenes 4, acrylic esters 5 and acrylonitriles 6 have been measured.Comparison with Hammett ?-values shows, that substituents at the non attacked vinylic carbon atom show polar effects mainly (Table 1).The effect of a substituent variation increases with increase of the reactivity of the alkenes (Table 2).Mesomeric and steric effects play only a minor role.
Selectivity of prim., sec. and tert. Alkyl Radicals in Addition Reactions
Giese, Bernd,Kretzschmar, Gerhard,Meixner, Juergen
, p. 2787 - 2795 (2007/10/02)
In reductions of alkylmercuric salts 4 and 5 with NaBH4 alkyl radicals 1 are formed as intermediates.The selectivity of prim., sec. and tert. radicals in addition reactions with alkenes 6-12 can be measured by this "mercury-method", because adduct radicals 13-19 form products 20-26 quantitatively.Dimerization, disproportionation, polymerization, trapping of oxygen and β-bond cleavage don't compete with the hydrogen transfer to 13-19.The measurements show, that alkyl radicals 1 are nucleophiles and that their selectivity increases in going from prim. to sec. and tert. radicals (Table 1).As long as steric effects are not important, reactivities and selectivities can be described by frontier molecular orbital theory.As a consequence of this theory selectivity increases with increasing reactivity.
