The prospects of cation transfer to chalcogen nucleophiles

In this study, we used computational quantum chemistry to investigate the cation affinity for a range of nucleophiles to gauge the possibility of using organochalcogens as catalysts for cation transfer (reference data and geometries are provided in the repository https://github.com/armanderch/ca176). In general, the calculated gas-phase cation affinities decrease in the order Cl+ > Br+ > I+ > carbon-centered cation, the anionic nucleophiles have significantly larger cation affinities than the neutral ones, sulfides have larger cation affinities than selenides, and solvation lowers the cation affinities and especially for anionic nucleophiles. These observations are consistent with general chemical intuitions. The energies for the resulting condensed-phase cation transfer reactions show that transferring a carbon-centered cation from a neutral source (e.g., Me2CO3) to a chalcogen nucleophile (e.g., Me2S) is thermochemically viable. However, they are associated with large kinetic barriers. Overall, we find that SeMeC6H5 may be a suitable catalyst for transferring a carbon-centered cation from an active source such as MeCO3R or MeSO4R. In this study, we also find that double-hybrid DFT methods, e.g., DSD-PBEP86 to be reasonable for the study of these cation transfer processes.