KI–Tetraethylene Glycol Complex as an Effective Catalyst for the Synthesis of Cyclic Thiocarbonates from Epoxides and CS₂

An efficient synthesis of cyclic thiocarbonates from epoxides and CS₂ under mild reaction conditions was achieved when a KI–tetraethylene glycol complex was used as a readily available and economic catalyst. The effects of various glycols and alkali metal halides were investigated in the present work to clarify the importance of both KI and tetraethylene glycol. The reaction mechanisms for the synthesis of cyclic thiocarbonates are discussed on the basis of the stereochemistry of the products.