Synthesis of new functionalized chiral ionic liquid and its organocatalytic asymmetric epoxidation in water

A new sulfur-functionalized chiral ionic liquid has been developed for the epoxidation reaction of aromatic aldehydes with benzyl bromide in water, furnishing desired trans-epoxides with excellent diastereoselectivity and enantioselectivity up to 72% ee. The organocatalyst could be easily reused for five times without remarkable decrease in yields and enantioselectivities.