Synthesis of new tetrahydropyridines catalyzed by Fe3O4@S-doped TiO2 via one-pot multi component Mannich reaction

Organic reactions promoted by recyclable solid catalysts have attracted much attention for their great economic and environmental importance in the chemical and pharmaceutical industries. Synthesis of highly substituted tetrahydropyridines has been developed using several approaches such as intramolecular Mannich reaction onto iminium ions. These compounds are biologically active and important in pharmaceutics [1-3]. In this study, synthesis of new tetrahydropyridines from the one-pot three component Mannich reaction between acetyl acetone, aromatic aldehydes and amines under neat conditions is described. This reaction catalyzed by Fe3O4@S-doped TiO2, as an efficient, reusable and heterogeneous catalyst (Scheme 1). The results showed that catalyst affected both on the rate of reaction and purity of products. Design and preparation of Fe3O4@S-doped TiO2 hollow nanospheres and optimization of the condition of the given reaction will be discussed in the congress.