Theoretical study of the addition of hydrogen cyanide to methanimine in the gas phase and in aqueous solution

We have performed a detailed study of the title reaction, which is the key step of one of the most realistic processes suggested for the prebiotic syn thesis of amino acids. From a methodological point of view, our results con firm the reliability of the integrated computational tool formed by the B3L YP density functional model and the polarizable continuum model for the des cription of solvent effects, From a more chemical point of view, the reacti on is quite unlikely in the gas phase due to the presence of significant re action barriers, whereas the aqueous medium lends to a more feasible mechan ism thanks to the preferential solvation of zwitterionic transition structu res. Both specific and bulk solvent effects play a role in determining the overall mechanism.