Multicomponent Reactions Promoted by Ecocatalyst from Metal Hyperaccumulating Plant Pluchea sagittalis

Abstract

Phytoremediation has been considered a sustainable environmental technology for heavy metals decontamination. In this work, we evaluated the metal contents by inductively coupled plasma optical emission spectrometry (ICP-OES) of three plant species collected in a mine in the Brazilian Amazonia area. Based on this analysis, Pluchea sagitallis leaves were selected to prepare metallic ecocatalysts. The leaf ashes and the obtained ecocatalysts were characterized by ICP-OES, X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2-physisorption measurements. Moreover, they were evaluated in the Biginelli and Hantzsch multicomponent reactions, furnishing the corresponding 3,4-dihydropyrimidin-2-(1H)-ones and 1,4-dihydropyridines with good to excellent yields. The best ecocatalyst was easily recovered and recycled in up to six reactions without a significant decrease in its performance.