Selective Ring-Opening Reaction of Epoxides with Sodium Borohydride in the Presence of Cyclodextrins in Aqueous Media

Abstract

Abstract In the presence of cyclodextrins (CDs), the ring-opening reaction of styrene oxide with NaBH4 in aqueous media proceeded smoothly to give 1-phenylethanol with high selectivity of up to 94%, and kinetic resolution of the racemic epoxide was observed. Kinetic studies suggest the resolution based on the different reaction rates between two enantiomers included in the CD’s cavity. The reaction of epoxides such as 1,2-epoxyindan and 1,2-epoxy-3-phenylpropane are also affected by the addition of CDs to proceed smoothly with high regioselectivities.