Ionic liquid-functionalized amphiphilic Janus nanosheets afford highly accessible interface for asymmetric catalysis in water

High oil/water interfacial area together with accessible interfaces for regents is the key to achieving efficient asymmetric catalysis in water. Herein, by taking advantage of the excellent interfacial activity of Janus nanosheets (JNS), as well as the unique compatibility of imidazolium ionic liquid (IL), we developed a series of IL -functionalized amphiphilic Janus mesosilica nanosheets which afford highly accessible reaction interfaces for highly enantioselective sulfoxidation in water. The JNS-typed chiral salen Ti IV catalysts were prepared by selectively decorating hydrophobic chiral salen Ti IV complex on one side of Janus mesosilica nanosheets through the imidazolium-based IL linker. Benefiting from the two-dimensional porous Janus structure, as well as the compatible IL linker, the IL -tagged JNS catalysts afforded high oil/water interfacial areas and highly accessible reaction interface for sulfides and H 2 O 2 , significantly accelerating asymmetric sulfoxidation in water using H 2 O 2 as an oxidant. In addition, they can be facilely recovered for stable reuse by simple centrifugation.