Silica supported perchloric acid: A mild and highly efficient heterogeneous catalyst for the synthesis of poly-substituted quinolines via Friedländer hetero-annulation

Abstract

Silica supported perchloric acid (HClO4-SiO2) is found to be a heterogeneous recyclable catalyst for the rapid and efficient synthesis of various poly-substituted quinolines in the Friedländer condensation of 2-aminoarylketones with carbonyl compounds and β-keto esters at ambient temperature. The catalyst can be reused at least three times.