An efficient one-pot synthesis of industrially valuable primary organic carbamates and N-substituted ureas by a reusable Merrifield anchored iron(ii)-anthra catalyst [FeII(Anthra-Merf)] using urea as a sustainable carbonylation source

Abstract

An efficient synthesis of primary carbamates and N-substituted ureas is explored with a newly developed heterogeneous polymer supported iron catalyst in the presence of a sustainable carbonylation source. The Merrifield anchored iron(II)-anthra catalyst [Fe^II(Anthra-Merf)] was synthesized by functionalization of Merrifield polymer followed by grafting of iron metal. The catalyst [Fe^II(Anthra-Merf)] was characterized by several techniques, like SEM, EDAX, TGA, PXRD, XPS, FTIR, CHN, AAS and UV-Vis analysis. The designed polymer embedded [Fe^II(Anthra-Merf)] complex is a remarkably successful catalyst for the synthesis of primary organic carbamates and N-substituted ureas by using safe carbonylation agent urea with different derivatives of alcohols and amines, respectively. The reported catalyst is a potential candidate towards contributing a satisfactory yield of isolated products under suitable reaction conditions. The catalyst is recyclable and almost non-leaching in nature after six runs with an insignificant drop in catalytic activity. Thus we found an economical and viable catalyst [Fe^II(Anthra-Merf)] for primary carbamates and N-substituted urea synthesis under moderate reaction conditions.