Periodic Mesoporous Silica-Supported Scandium Triflate as a Robust and Reusable Lewis Acid Catalyst for Carbon–Carbon Coupling Reactions in Water

Abstract

Phenyl-bridged periodic mesoporous organosilica modified with sodium benzenesulfonate groups (NaSO3Ph-PMO) was frabicated by template-assembled co-condensation and subsequent ion-exchange processes. This functionalized support efficiently anchored scandium triflate to generate a mesoporous Lewis acid catalyst (Sc(OTf)2-SO3Ph-PMO). It exhibited superior catalytic reactivity compared to those of the homogeneous catalyst scandium triflate and Sc(OTf)2-SO3Ph-SBA-15, without the phenyl groups inside the mesoporous wall of the water medium Barbier–Grignard and Mukaiyama–Aldol reactions. The physico–chemical characterizations demonstrated that its excellent catalytic performance was due to its ordered mesoporous channel and hydrophobicity microenvironment, which could stabilize and concentrate the substances as well as decrease intrinsic mass transfer resistance. Furthermore, the Sc(OTf)2-SO3Ph-PMO catalyst retained high catalytic reactivity even after 10 reuses, confirming its excellent catalytic stability.