A bifunctionalized organic-inorganic hybrid silica: synergistic effect enhances enantioselectivity.

An imidazolium-based bifunctional heterogeneous catalyst exhibits excellent catalytic efficiency in asymmetric transfer hydrogenation of aromatic ketones in aqueous medium. The superior catalytic performance and the enhanced enantioselectivity is attributed to the synergistic effect of salient imidazolium phase-transfer function and the confined nature of the chiral organoiridium catalyst.