Unexpected concerted two-proton transfer for amination of formic acid to formamide catalysed by Mn bipyridinol complexes

A density functional theory study on hydrogenation of carbon dioxide to formate and formamide catalysed by a Mn bipyridinol complex reveals an unexpected metal-ligand cooperation mechanism with concerted two-proton transfer processes for the activation of diethylamine and formic acid, as well as the formation of formamide and water. Both ortho-O atoms in the bipyridinol ligand act as proton relay sites for the simultaneous transfer of two protons for the breaking of N-H and C-O bonds and the formation of a C-N bond.