Amine oxidation. Part VIII. Evidence for intramolecular hydrogen-atom transfer in amine radical cations

Abstract

Reaction of the N-oxide of R₂BuN (R = Me or Bu) with iron(II) ion gives the hydroxy-derivatives R₂N·[CH₂]₂·CH(OH)Me and R₂N·[CH₂]₃·CH₂·OH, as well as the parent amine and a secondary amine. Evidence is presented that the hydroxy-compounds are formed from the amine radical cation R₂BuN⁺˙via intramolecular hydrogen-atom transfer which occurs specifically at the terminal carbon of the butyl group; the resulting carbon radical yields the primary alcohol by way of one-electron oxidation, and the secondary alcohol partly by way of one-electron oxidation and intramolecular rearrangement and partly via intermolecular hydrogen-atom abstraction.