Organorhodium‐Functionalized Periodic Mesoporous Organosilica: High Hydrophobicity Promotes Asymmetric Transfer Hydrogenation in Aqueous Medium

摘要: Three organosilica-bridged periodic mesoporous organosilicas were prepared by the immobilization of a chiral N-sulfonylated diamine-based organorhodium complex within their silicate network. Structural analysis and characterization confirmed well-defined single-site active rhodium centers, whilst electron microscopy revealed highly ordered hexagonal mesostructures. Among these three different organosilicas, ethylene-bridged organosilica catalyst exhibited excellent heterogeneous catalytic activity high enantioselectivity in aqueous asymmetric transfer hydrogenation aromatic ketones. This superior performance was attributed to its salient hydrophobicity, comparable relative homogeneous derived from confined nature sites. Furthermore, this could be conveniently recovered reused at least 12 times without loss activity. feature makes attractive for practical organic synthesis an environmentally friendly manner. study offers general way optimizing bridged moiety thereby enhancing catalysis.