Direct synthesis of cyclic carbonates from olefins and CO₂ catalyzed by a MoO₂(acac)₂-quaternary ammonium salt system

A highly efficient synthesis of cyclic carbonates from olefins and CO₂ has been achieved by the use of a molybdenyl acetylacetonate (MoO₂(acac)₂)–quaternary ammonium salt catalytic system with tert-butyl hydroperoxide as an oxidant through a one-pot multistep process. This simple and cheap method can be applied to various olefins, such as 1-octene, 1-hexene, allyl chloride, cyclohexene and styrene, affording the highest yields in comparison with the data reported previously except for styrene. A plausible mechanism is proposed based on the results.