A theoretical study on the mechanism of a novel one-carbon unit transfer reaction

The mechanism of one-carbon unit transfer reaction between tetrahydrofolate coenzymes model compound (e.g., benzimidazolium) and Grignard reagent has been investigated employing the DFT and B3LYP/6-31G* levels of theory. Three consecutive reactions leading to major products N,N'-dimethyl-ophenylenediamine and acetone have been proposed and discussed. For these reactions, the structure parameters, vibrational frequencies, and energies for each stationary point have been calculated, and the corresponding reaction mechanism has been given by the potential energy surface, which is drawn according to the relative energies. The calculated results show that the corresponding major products N,N'-dimethyl-ophenylenediamine and acetone are in agreement with experimental findings, which provided a new illustration and guidance for these reactions.