Cleavage and Formation of C F Bonds by an Iridium Complex fullCatalysis by transition metal complexes is key to the transformations of organic molecules ranging from fuels to fine chemicals. The presence of C-F bonds is critical to the function of many pharmaceuticals, agrochemicals, and other materials.

In this paper in the journal Science, Jongwook Choi, David Wang, and Sabuj Kundu, working with Profs. Karsten Krogh-Jespersen and Alan Goldman, report the discovery of the first example of oxidative addition of a C(sp3)-F bond to a transition metal center. The mechanism of this reaction, remarkably, proceeds via the oxidative addition of a C-H bond followed by C-to-Ir migration of fluorine. Equally surprising is the conclusion that the reverse reaction, C-F bond formation must proceed in this case via the microscopic reverse, beginning with C-to-Ir migration of a methyl hydrogen.

The discovery of this reaction and the novel mechanism elucidated opens potential new avenues toward the catalytic formation and transformation of this important class of molecules.

Choi, J., Wang, D. Y., Kundu, S., Choliy, Y., Emge, T. J., Krogh-Jespersen, K. & Goldman, A. S. Net Oxidative Addition of C(sp3)-F Bonds to Iridium via Initial C-H Bond ActivationScience 332, 1545-1548, doi:10.1126/science.1200514 (2011).

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Year of Research Highlight: 2011