Theoretical study of the reaction mechanism of the uncatalyzed epoxidation of alkenes by iodosylbenzene

Abstract

The origin of the barrier for the uncatalyzed epoxidation of alkenes by iodosylbenzene is examined from a computational point of view. The reaction of a monomeric unit with ethylene presents a very low barrier, in disagreement with experimental data indicating the requirement of a catalyst. The polymeric structure of iodosylbenzene was then analyzed and the importance of the presence of a terminal hydration water in its linear structure confirmed. The reaction of a model dimer with ethylene is shown to have a high barrier, in good agreement with experiment. Implications of this result with respect to the nature of the catalytic mechanism are briefly discussed.