Chitosan-Coated Metal–Organic-Framework Nanoparticles as Catalysts for Tandem Deacetalization–Knoevenagel Condensation Reactions

A series of chitosan (CS)-coated metal–organic-framework (MOF) nanoparticles, which combined excellent chemical stability, thermal stability, and recyclability, were synthesized by an in situ growth method. The CS-coated MOF nanoparticles consist of stable MIL-101(Cr) as the core and CS as the shell, with MIL-101(Cr) providing Lewis acidic sites and CS providing both Brønsted acidic sites and Lewis basic sites. Thus, the CS-coated MOF nanoparticles exhibited outstanding catalytic properties for a one-pot tandem deacetalization–Knoevenagel condensation reaction, and both the catalytic activity and selectivity were remarkable.