The introduction of fluorine into an organic molecule imparts unique physicochemical properties. Not surprisingly, fluorine is increasingly incorporated into new drugs and agrochemicals. However, aryl fluoride building blocks are only available through synthesis. The ability to cross-couple polyfluoroaromatics selectively could provide a convenient route to functionalized fluoroaromatics. We report herein the first examples of Pt-catalyzed cross-coupling of aryl fluorides. The methylated products can potentially serve as precursors to a wide range of functionalized fluorinated small molecules.

CH 3 ) 2 Pt(µ-SMe 2 )] 2 catalyzes the formation of aryl methyl ethers Via selectiVe C-F bond actiVation of polyfluoroarylimines. This reaction is functional group tolerant and proceeds in good to excellent yields. The optimization and preliminary substrate scope of this process are described.The activation of strong carbon-element bonds remains a significant challenge in organometallic chemistry. In recent years, platinum-based complexes have shown increasing potential for selective carbon-atom bond activation. Detailed mechanistic investigations of these transformations have brought new understanding to the range of reactivity accessible. Significant advances in platinum chemistry include carbon-hydrogen 1 and carbon-halogen bond activation, 2 complexes of heavier element species, 3 reductive elimination from both Pt(II) 4 and Pt(IV) species, 5 dehydrogenation, 6 and a range of applications such as sensors for SO 2 and other gases, 7 biosensors, 8 and photochemical products. 9 Moreover, the use of Pt(II)/Pt(IV) redox cycles in catalysis is becoming increasingly common. In particular, we have been interested in using Pt(II) complexes to catalyze the activation and subsequent functionalization of aryl C-F bonds. Although several examples of stoichiometric 1a,r,2b,10 and catalytic C-F activation have been reported, 11 only limited examples for the catalytic cross-coupling of polyfluoroarenes have emerged. 12 We recently reported that [(CH 3 ) 2 Pt(µ-SMe 2 )] 2 catalyzes the methylation of a wide range of fluorinated aryl Crespo, M.; Granell, J.; Vizcarro, A.; Zafrilla, J.; Font-Bardia, M.; Solans, X. Albrecht, M.; Lutz, M.; Schreurs, A. M. M.; Lutz, E. T. H.; Spek, A. L.; van Koten, G. Dalton Trans. 2000, 3797-3804. (c) Albrecht, M.; Lutz, M.; Spek, A. L.; van Koten, G. Nature (London) 2000, 406, 970-974. (d) Albrecht, M.; Gossage, R. A.; Lutz, M.; Spek, A. L.; van Koten, G.

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 (CH 3 ) 2 Zn via transmetalation. Subsequent reductive elimination from the Pt(IV) species generates a new sp 2 -sp 3 C-C bond. In addition, we have identified a species present during the catalytic reaction and propose this to be the catalyst resting state.

A series of Pt­(IV) complexes relevant to catalytic C–F activation have been prepared and structurally characterized. PtIV–F complexes, formed by C–F activation, underwent transmetalation with Me2Zn to generate Me3PtIV fluoroaryl complexes. In all cases, the Me3PtIV complex underwent reductive elimination to generate methylated organic products. The reactivity of both PtIV–F and Me3PtIV fluoroaryl complexes was strongly affected by the electronic nature of the cyclometalated fluoroaryl ligand.

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