Abstract: This paper reports a novel and convenient synthetic route to styrene carbonate from styrene and CO₂ catalyzed by quaternary ammonium(phosphonium) salts, which avoids the isolation of intermediate epo-xide. This route involves two sequential reactions: epoxidation of styrene and cycloaddition of CO₂ to epoxide. With tetrabutylammonium bromide as the catalyst, oxidants have a strong effect on the carbonate yield. The influences of reaction temperature, reaction time, CO₂ pressure and catalyst amount are studied in detail. Under mild reaction conditions(80 ℃, 6 h, CO₂ pressure 1 MPa), the yield of styrene carbonate can be increased to 38% with TBAB without any organic solvent. Moreover, the synergistic effect of bulky ammonium cation and moderate nucleophilicity of anion results in its good performance in the one-pot synthesis of styrene carbonate.

Key words: Styrene carbonate, One-step synthesis, Styrene, CO₂, Quaternary ammonium bromide