A Cooperative Rhodium/Secondary Phosphine Oxide [Rh/P(O)nBu(2)] Template for Catalytic Hydrodefluorination of Perfluoroarenes

The selective activation of C-F bonds under mild reaction conditions remains an ongoing challenge of bond activation. Here, we present a cooperative [Rh/P(O)nBu(2)] template for catalytic hydrodefluorination (HDF) of perfluoroarenes. In addition to substrates presenting electron-withdrawing functional groups, the system showed an exceedingly rare tolerance for electron-donating functionalities and heterocycles. The high chemoselectivity of the catalyst and its readiness to be deployed at a preparative scale illustrate its practicality. Empirical mechanistic studies and a density functional theory (DFT) study have identified a rhodium(I) dihydride complex as a catalytically relevant species and the determining role of phosphine oxide as a cooperative fragment. Altogether, we demonstrate that molecular templates based on these design elements can be assembled to create catalysts with increased reactivity for challenging bond activations.

Automated summary

In this study, a cooperative [Rh/P(O)nBu(2)] template was used for the catalytic hydrodefluorination (HDF) of perfluoroarenes under mild reaction conditions. The system showed high chemoselectivity and practicality, even in the presence of electron-donating functionalities and heterocycles. Mechanistic and theoretical studies identified a rhodium(I) dihydride complex as the catalytically relevant species and the crucial role of phosphine oxide as a cooperative fragment. Overall, this work demonstrates the potential of molecular templates for enhancing the reactivity in challenging bond activations.