Insight into the Mechanism of Platinum-Catalyzed Cross-Coupling of Polyfluoroaryl Imines

Abstract

We recently reported the first examples of Pt-catalyzed methylation of polyfluorinated arenes as a means to generate partially fluorinated aromatic building blocks. The reaction is selective for cleavage of C−F bonds ortho to an imine substituent and allows for preferential cleavage of C−F bonds in the presence of considerably weaker bonds (e.g., C−Br). We report herein the proposed mechanism for this reaction. Initial C−F activation generates a Pt(IV)−F intermediate, which then reacts with (CH3)2Zn via transmetalation. Subsequent reductive elimination from the Pt(IV) species generates a new sp2−sp3 C−C bond. In addition, we have identified a species present during the catalytic reaction and propose this to be the catalyst resting state.