Synthesis of thiiranes from oxiranes in water using polymeric cosolvents

Poly(vinylamine) (PVA) and poly(allylamine) (PAA) were prepared and used as polymeric cosolvents. Oxiranes were converted efficiently to the corresponding thiiranes under mild reaction conditions in water with ammonium thiocyanate (NH4SCN) using these polymeric cosolvents. The polymeric cosolvents are reusable.