An efficient FeCl3/SiO2 NPs as a reusable heterogeneous catalyzed five-component reactions of tetrahydropyridines under mild conditions

A convenient, simple, and multicomponent coupling strategy has been developed for the synthesis of highly functionalized tetrahydropyridines using FeCl₃/SiO₂ NPs as catalyst. This method demonstrated five-component coupling reactions of 1,3-dicarbonyl compounds, aromatic aldehydes and amines without an inert atmosphere. Atom economy, good yields, environmentally benign, and mild reaction conditions are some of the important features of this protocol. Notably, this catalyst could be recycled and reused for several times without noticeably decreasing the catalytic activity.