Understanding the Hydride Abstraction From Alkanes Promoted by Trityl Cations

The poorly understood factors governing the reactivity of trityl cations are quantum chemically investigated by means of density functional theory calculations. To this end, the hydride abstraction reactions from a wide variety of alkanes are explored, with a focus on the processes mediated by the recently isolated, highly electrophilic perfluorotrityl cation. By using the combination of the activation strain model of reactivity and the energy decomposition analysis, it is found that the orbital interactions involving the donation of electron density from the H‐donor to the carbocation dominate the transformation. Despite that, the energy penalty associated with the geometrical deformation of the reactants also plays a crucial role and it is behind, for instance, the complete regioselectivity observed in the process involving cyclohexane. The insights gained in this study are also used to predict new systems enabling hydride abstraction reactions with even lower barriers than those involving the highly active perfluorotrityl cation.