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 effi-cient 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 reac-tion 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 H2O2, significantly accelerating asymmetric sulfoxidation in water using H2O2 as an oxidant. In addition, they can be facilely recovered for stable reuse by simple centrifugation. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

The use of IL-functionalized amphiphilic Janus mesosilica nanosheets, prepared by decorating JNS with IL linker, allows for highly enantioselective sulfoxidation in water, providing highly accessible reaction interfaces.