The MAO-B catalyzed α-carbon oxidation of amines has been proposed to proceed via either a single electron transfer (SET) or hydrogen atom transfer (HAT) pathway. In an attempt to distinguish between these pathways, we have examined the α-carbon oxidation of a series of 4-substituted 1-methyl-1, 2, 3, 6-tetrahydropyridine derivatives, compounds which are MAO-B substrates, employing chemical models of the SET pathway [using the PF6− ...