A heteropolyacid-based ionic liquid immobilized onto magnetic fibrous nano-silica as robust and recyclable heterogeneous catalysts for the synthesis of tetrahydrodipyrazolopyridines in water

The application of a heteropolyacid containing an ionic liquid based organosilica (Fe3O4/KCC-1/IL/HPW) catalyst for the synthesis of tetrahydrodipyrazolopyridines is demonstrated. Because of the amplification effect of the IL, high loading capacities of the heteropolyacid were achieved. The catalyst system could be successfully recovered and reused several times without any significant decrease in activity and selectivity. The synthesized Fe3O4/KCC-1/IL/HPW nanocatalyst exhibited excellent catalytic activity in multicomponent reactions under mild conditions due to the easy accessibility of the active sites.