Allylic oxidation of olefins by cobalt (III), manganese(III), and cerium (IV) acetates in acetic acid in the presence of sodium bromide

Abstract

The effect of added sodium bromide on the allylic oxidation of olefins by cobalt(III), manganese(III), and cerium(IV) acetates has been studied. Sodium bromide strongly accelerated the oxidation of cyclohexene by these oxidants to give cyclohex-2-enyl acetate in good yield. Only one product was obtained in the oxidation of cycloalkenes, but two allylic acetates were obtained in the oxidations of methyl-substituted cyclohexenes, which have two kinds of allylic hydrogen. A mechanism involving hydrogen abstraction from allylic sites by bromine radicals is suggested.