Ag nanoparticles grafted porous organic polymer as an efficient heterogeneous catalyst for solvent-free A3 coupling reactions

Designing of low cost catalytic system for new C-C/C-N/C-O bond formation reactions is very challenging in synthetic organic chemistry. Herein, we report a new Ag NPs immobilized porous organic polymer (POP) material Ag-NPs@PDVTA-1 by grafting of Ag nanoparticles at the surface of a POP material PDVTA-1. PDVTA-1 has been synthesized via radical co-polymerization of divinylbenzene and triallylamine under solvothermal reaction conditions. PDVTA-1 as well as the Ag-loaded catalyst Ag-NPs@PDVTA-1 are fully characterized to understand their physico-chemical properties. Ag-NPs@PDVTA-1 is used as heterogeneous nanocatalyst for the one pot three component A3 coupling reaction of aldehyde, secondary amine and terminal alkyne for the synthesis of a wide range of propargylamine derivatives under mild and eco-friendly reaction conditions. The desired products were obtained in high yields over this environmentally safe catalyst under optimized reaction conditions. Remarkably high specific surface area of Ag-NPs@PDVTA-1 (694 m(2)g(-1)) and its highly accessible catalytically active Ag-sites in the nano-architecture potentially makes it an efficient catalyst as reflected from the respective turn over numbers. The catalyst was collected and reused for several reaction cycles without any noticeable decline in its catalytic activity, suggesting its high merit in heterogeneous catalysis for the synthesis of value added C-C/C-N coupling products via one pot coupling reaction.

Automated summary

Designing a low-cost catalytic system for new C-C/C-N/C-O bond formation reactions is challenging. In this study, a new Ag NPs immobilized porous organic polymer material was prepared and used as a heterogeneous nanocatalyst for the synthesis of propargylamine derivatives. The catalyst exhibited high catalytic activity, a large specific surface area, and could be reused for multiple reaction cycles.