Metal chloride impregnated-pillared clay for coumarin synthesis and anion intercalated Ni/Zn catalyst for michael addition reactions

Abstract

Metal oxide-pillared montmorillonites were synthesized by intercalation method and calcination. The impregnation with metal chloride (CrCl3 and NdCl3) was carried out with calcination. The synthesized clays were characterized by powder X-ray diffraction, N2 adsorption-desorption and temperature programmed desorption of ammonia techniques. These synthesized clays were utilized as catalysts for the synthesis of coumarins, isomerization of epoxides and synthesis of acetonides from epoxides. The synthesized clays provided considerably higher catalytic activities than the parent clay. The optimized conditions for these acid-catalyzed reactions were scrutinized. These reactions could be expediently proceeded using synthesized clay catalysts to provide good to excellent yield and selectivity of the corresponding products under mild reaction conditions. In addition, the alkylcarboxylate anion-intercalated NiZn catalysts were prepared by intercalation method, characterized by powder X-ray diffraction and utilized for Michael reaction. The synthesized NiZn catalysts furnished high catalytic activities.