Hierarchical Silica Inverse Opals as a Catalyst Support for Asymmetric Molecular Heterogeneous Catalysis with Chiral Rh?diene Complexes

The efficacy of heterogeneous catalysis relies heavily on diffusion and distribution reactants within catalyst supports. However, the presence confinement, essential for reaction selectivity, drastically slows down molecular transport. Here, macro-mesoporous silica inverse opal (SiO2?IO) films were used as a model system to study rather unexplored infiltration behavior using probe molecule resembling via confocal laser scanning microscopy (CLSM). CLSM analysis revealed homogeneous tracer in SiO2?IO attachment both transport mesopores. Bulk support was mono- bis-functionalized chiral Rh-diene complexes, catalytic activity selectivity with respect studied. Lower enantioselectivity observed ligand due entanglement reduced accessibility active site, while mono-functionalized gave an excellent 94 %ee asymmetric 1,2-addition triphenylboroxine N-tosylimines could be recycled up three times.