Synthesis of Biginelli adducts using a Preyssler heteropolyacid in silica matrix from biomass building block

Abstract

An efficient, suitable and high yielding method has been developed employing the use of the renewable platform molecule furfural for the synthesis of Biginelli derivatives via a three-component domino reaction through a combination of aldehydes (furfural), β-ketoesters, and urea or thiourea using Preyssler heteropolyacid H14NaP5W29MoO110 encapsulated in a silica framework as the catalyst. The reaction was carried out under solvent-free conditions, affording very good yields using thermal and microwave heating. Atom economy, an environmentally benign procedure, reuse of catalysts, and short reaction time are some of the important features of this protocol. The Preyssler catalyst embedded in the silica matrix is insoluble in polar and apolar media, which allows easy removal of the reaction products without affecting its catalytic activity.