Manganese(II) complexes of imidazole based-acetamide as homogeneous and heterogenised catalysts for alkene epoxidation with H2O2

An acetamide derivative which bears two terminal imidazole rings has been synthesized. This biomimetic ligand, N-[2-(1H-imidazol-4-yl)-ethyl]-2-({[2-(1H-imidazol-4-yl)-ethylcarbamoyl]-methyl}-amino)-acetamide, has been also grafted on silica surface via covalent bond. The supported and non-supported biomimetics reacted with manganese(II) ions leading to the formation of the corresponding metal complexes. These have been evaluated as catalysts for alkene epoxidation with H2O2 in the presence of ammonium acetate as an additive. Our data showed that the homogeneous and the supported systems are able to overcome the competitive H2O2 dismutation, by the use of only two times H2O2 with respect to substrate, favouring productive alkene epoxidations to a significant extent.