Porous and Robust Lanthanide Metal-Organoboron Frameworks as Water Tolerant Lewis Acid Catalysts

Abstract

Porous and robust 12-connected metal–organic frameworks (MOFs) were constructed by linking tetranuclear lanthanide (Ln) carbonate clusters with organoboron-derived tricarboxylate bridging ligands. The high-connectivity Ln-MOFs feature remarkable thermal and hydrolytic stability and a large number of isolated Lewis acid B­(III) and Ln­(III) sites on the pore surfaces. The Nd-MOF assisted with sodium dodecylsulfate was found to be highly effective, recyclable, and reusable heterogeneous catalyst for the carbonyl allylation reaction, the Diels–Alder reaction, and the Strecker-type reaction in water. The transformations were cocatalyzed by Nd­(III) and B­(III) Lewis acids, with activities much higher than those of the individual organoboron and lanthanide counterparts and their mixture. This work highlights the potential of generating highly efficient water-tolerant solid catalysts via heterogenization of different weak and/or mild Lewis acids in confined spaces of robust MOFs