Efficient synthesis of dihydropyranochromene derivatives via nanocopper immobilized on Zn/Cr-LDH functionalized with poly(p-phenylenediamine)

Abstract

A new catalyst, poly(p-phenylenediamine) functionalized with copper nanoparticles stabilized on layered double hydroxide (LDH@poly(p-phenylenediamine)@CuI), was prepared. The structure of the new catalyst was identified and confirmed using different analyzes such as FESEM, EDX, XRD, TGA and elemental mapping. The efficiency of the mentioned catalyst was confirmed in the three-component one-pot synthesis of various derivatives of dihydropyrano[3,2-c]chromene in aqueous ethanol solvent. The structure of the synthesized products was confirmed using infrared spectrometry (FT-IR), nuclear magnetic resonance (1H NMR and 13C NMR) and Mass techniques. High yield of products, short reaction time, easy purification, reuse of catalyst, and the use of a soft reaction method can be considered as the main advantages of this method. Additionally, this catalyst was recycled four times without a significant loss of catalytic power.