Enhanced Organocatalytic Processes through an Engineered Acid‐Base Site Bifunctional Pore in a Zirconium Metal‐Organic Framework

Abstract

AbstractThis work introduces a robust acid‐base catalytic system based on the zirconium‐based metal‐organic framework (Zr‐MOF) MOF‐808, selected for its open structure, high stability, and low presence of structural defects compared to other Zr‐MOFs. Four bifunctional benzoate ligands bearing free carboxylic acid (‐COOH) and nitrogen‐containing groups were introduced into the MOF‐808 using solvent‐assisted ligand exchange methods. Unlike other materials, the acid and base sites in the bifunctional MOF‐808 materials are situated in the same capping ligand, leading to a bifunctional behavior between the two neighboring sites. The system was tested for Knoevenagel condensation and deacetylation‐Knoevenagel tandem reactions, demonstrating high catalytic activity and excellent yields. Additionally, computational modeling provided insights into the catalytic mechanism and the role of the acid‐base sites. The study provides a better understanding of the unique behavior of the bifunctional MOF‐808 catalyst and offers prospects for designing new and efficient catalytic systems for organocatalysis.