Pure and Applied Chemistry

Oxybromination reaction of styrene was performed in a two-phase system of water/ionic liquids (ILs). The aim of the work was to make the mild and efficient two-phase system previously developed for the vanadium(V)-catalyzed oxybromination of alkenes, inspired by the activity of haloperoxidase enzymes, even more interesting from a sustainable point of view. As in that case, a brominating intermediate was formed from the metal catalyst, H₂O₂, and bromide ion in the acid aqueous phase, but chlorinated solvents were replaced with ILs.

[bmim⁺][PF₆^-], [bm₂im⁺][PF₆^-], [bmim⁺][BF₄^-], [bmim⁺][CF₃SO₃^-], and [bmim⁺][(CF₃SO₂)₂N^-] were tested. We report on interesting results in terms of reaction rates and selectivities.