Carbonate Formation from Oxiranes and Carbon Dioxide Catalyzed by Organotin Halide-Tetraalkylphosphonium Halide Complexes

Cycloaddition of carbon dioxide to oxiranes was excellently promoted by the complexes of organotin halides and tetraalkylonium halides, while either components of the complexes had no catalytic activity individually. Particularly, the complex composed of Bu3SnI–Bu4PI was the most favorable catalyst, yielding a variety of fivemembered cyclic carbonates under neutral and mild conditions.