Solid Heterogeneous Catalysts Based on Sulfuric Acid and Transition-Metal Salts: Synthesis of Bioactive Heterocycles

Synthesis of bioactive heterocycles using reusable heterogeneous catalyst HClO4–SiO2 under solvent-free conditions

“…Low cost, environment friendly, easy to handle, easy catalyst separation and regeneration, thermal stability, and long catalytic life are some of the other important features of the solid-supported catalysts (3). Solid-supported reagents are expected to be performed better than the individual reagent because of the increased effective surface area of the reagent, their activity and selectivity (4). Among the solid-supported catalytic systems, perchloric acid adsorbed on silica gel (HClO 4 -SiO 2 ) is found in various organic functional group transformations and also in the synthesis of many bioactive heterocycles (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15).…”