Highly efficient and recyclable basic mesoporous zeolite catalyzed condensation, hydroxylation, and cycloaddition reactions

Crystalline mesoporous ZSM-5 zeolite was prepared in the presence of 1,4-diazabicyclo[2.2.2]octane derived multi-cationic structure directing agent. The calcined form of the mesoprous zeolite was treated with NH₄OH to obtain basic mesoporous ZSM-5. Catalyst was characterized by the complementary combination of X-ray diffraction, N₂-adsorption, electron microscopes, and temperature programme desorption techniques. Catalytic activity of the basic mesoporous ZSM-5 was systematically assessed using Knoevenagel condensation reaction for the synthesis a wide range of substituted styrene. Applications of the catalyst were investigated in the benzamide hydroxylation for the synthesis of carbinolamides and one-pot, multi-component condensation reaction for the synthesis of naphthopyrans. Finally, the catalyst was evaluated in the cycloaddition of CO₂ to epoxide for the synthesis of cyclic carbonates. Recycling study shows that no significant decrease in the catalytic activity was observed after five recycles.