Computational mechanism investigation of Bi(i)/Bi(iii) redox-catalyzed hydrodefluorination (HDF) of polyfluoroarenes

Abstract

As an Earth-abundant and inexpensive main group element, the redox properties of bismuth are still under-explored. Here, we investigated a bismuth(I)-catalyzed hydrodefluorination reaction in detail using density functional theory (DFT) methods. Calculations indicate that although reductive elimination has a moderate energy barrier (about 20.45 kcal mol⁻¹), oxidative addition is crucial to this transformation, which correlates well with the main product yield. The excellent active bismuth catalyst does not effectively reduce the reductive elimination barrier, but promotes the reaction rate and yield by significantly lowering the oxidative addition barrier. Meanwhile, we also found that the metal bismuth is well coordinated with the nitrogen atoms of the N–C–N pincer ligand, delocalization of the 6p electron on bismuth to the benzene ring is weakened, and bismuth has a lower electropositivity, which will be more beneficial for oxidative addition, resulting in the stronger catalytic activity.