Multifunctional gold nanoparticles@imidazolium-based cationic covalent triazine frameworks for efficient tandem reactions

Abstract

Tandem catalytic reactions have attracted extensive interest because of their ability to reduce reaction steps, energy consumption, and waste. However, the construction of highly efficient tandem catalytic systems is still a significant challenge due to the problematic integration of multiple active sites in one reaction system and the incompatibility of different reaction conditions. Although metal nanoparticles (MNPs) supported on porous framework materials have shown excellent catalytic performances in various reactions, their cooperative catalysis for tandem reactions is rarely reported. In this work, ultra-fine gold nanoparticles (AuNPs) stabilized by imidazolium-functionalized cationic covalent triazine frameworks (ICTFs) were employed as multifunctional catalysts for a tandem reaction completed cooperatively by Lewis acid and base sites and Au species. The multifunctional catalyst, Au@ICTF, obtained exhibited excellent catalytic activity and selectivity in a tandem deacetalization-Knoevenagel condensation-reduction reaction under mild conditions, promoted by Lewis acid and base in ICTF and AuNPs, respectively. To the best of our knowledge, this is the first report using CTFs as multifunctional catalysts with multiple active sites to achieve catalysis of a tandem reaction cooperatively.