[Bmim]PF6: A Novel and Recyclable Ionic Liquid for Conversion of Oxiranes to Thiiranes in Aqueous Media

Abstract
A variety of epoxides respond rapidly with potassium thiocyanate in [bmim]PF6−H2O (2:1) solvent system at room temperature under mild and convenient conditions to produce the corresponding thiiranes in high to quantitative yields. Enhanced rates, improved yields, and recyclability of ionic liquids are the remarkable features observed in ionic liquids (ILs). The use of ionic liquids for this transformation avoids the use of heavy metal halides as promoters and chlorinated hydrocarbons as solvents. The ionic liquid was recycled in five to six subsequent runs with gradual decrease in activity.