Mannich metal complex: Synthesis, reaction mechanism and computational studies

Abstract

Metal mediated Mannich aminomethylation reaction involving metal(II)glycinato complex, formaldehyde, and ethyl acetoacetate (EAA) was carried out under mild aqueous conditions. Under the optimized condition, the reaction yielded only a single Mannich base product in a moderate yield without any contamination with the aldol condensation by-product. The Mannich base product obtained was characterized and confirmed by elemental analysis, UV–Vis spectroscopy, IR, ESI-MS, ESR, and GCMS–. The structure of the Mannich base product was investigated by Density Functional Theory (DFT). The structure interpretation of the product from the DFT data supported the proposed structure and was found to have an N2O2 four coordination square planar geometry around the Cu ion. HOMO and LUMO energy values for the product complex were calculated and the optimized condition for the maximum yield of the product was determined.