Understanding the catalysis by bis-selenonium cations as bidentate chalcogen bond donors

The mode of activation and catalysis bidentate bis-selenonium cations have been computationally explored in detail by means Density Functional Theory calculations. To this end, the parent Diels–Alder cycloaddition reaction between cyclohexadiene methyl vinyl ketone is compared to analogous mediated selenonium cations. It found that, although catalyst induces a significant stabilization LUMO dienophile, observed acceleration process not due an enhancement orbital interactions reactants but remarkable reduction both steric (Pauli) repulsion them destabilizing strain energy. Issues such as origin endo:exo selectivity transformation influence nature tether connecting selenium centers on activity catalysts are also analyzed detail.