A chiral diamine-based homogeneous cationic rhodium catalyst was developed and two heterogeneous cationic rhodium catalysts were obtained via the encapsulation of the homogeneous cationic rhodium catalyst within Me-SBA-15 and Me-SBA-16. All these catalysts presented excellent catalytic activities and high enantioselectivities in ultrasoundpromoted asymmetric transfer hydrogenation of aromatic ketones and represent a successful use of the ion-pair immobilization strategy. More importantly, the encapsulation of the cationic rhodium functionality within Me-SBA-16 had an obvious high recyclability, in which the recycled catalyst could be reused nine times without significantly affecting its enantioselectivity, showing good potential in industrial application.

A functionalized periodic mesoporous organosilica with incorporated chiral bis(cyclohexyldiamine)-based Ni(II) complexes within the silica framework was developed by the co-condensation of (1R,2R)-cyclohexyldiamine-derived silane and ethylene-bridge silane, followed by the complexation of NiBr(2) in the presence of (1R,2R)-N,N'-dibenzylcyclohexyldiamine. Structural characterization by XRD, nitrogen sorption, and TEM disclosed its orderly mesostructure, and FTIR and solid-state NMR spectroscopy demonstrated the incorporation of well-defined single-site bis(cyclohexyldiamine)-based Ni(II) active centers within periodic mesoporous organosilica. As a chiral heterogeneous catalyst, this functionalized periodic mesoporous organosilica showed high catalytic activity and excellent enantioselectivity in the asymmetric Michael addition of 1,3-dicarbonyl compounds to nitroalkenes, comparable to those with homogeneous catalysts. In particular, this heterogeneous catalyst could be recovered easily and reused repeatedly up to nine times without obviously affecting its enantioselectivity, thus showing good potential for industrial applications.

A periodic mesoporous organosilica (PMO) with chiral cyclohexyldiamine‐based nickel(II) complexes incorporated within the silica framework was prepared through a co‐condensation of (1R,2R)‐cyclohexyldiamine‐derived silane and Ph‐bridged silane followed by complexation of nickel(II) bromide in the presence of (1R,2R)‐N,N′‐dibenzylcyclohexyldiamine. Structural analyses by X‐ray powder diffraction, nitrogen sorption and transmission electron microscopy disclosed its orderly mesostructure while characterization by solid‐state NMR and X‐ray photoelectron spectroscopy demonstrated the well‐defined single‐site chiral bis(cyclohexyldiamine)‐based nickel(II) active centers incorporated within the PMO material. In particular, as a heterogeneous chiral catalyst, this periodic mesoporous organosilica showed high catalytic activity and excellent enantioselectivity in asymmetric Michael addition of 1,3‐dicarbonyl compounds to nitroalkenes (more than 92% conversions and up to 99% ee values). More importantly, this heterogeneous catalyst could be recovered easily and reused repeatedly nine times without obviously affecting its ee value, showing good potential for industrial applications.