44147-AC3
Transition Metal-Templated Reduction of Carbon-Fluorine Bonds: A New General Route to Unsaturated Fluorocarbon Ligands
We have followed up on our initial discovery that transition metal carbene complexes containing two trifluoromethyl substituents could be prepared and isolated; the complex Ir[=C(CF3)2]Cp*(CO) was prepared by reduction of Ir[CF(CF3)2]Cp*(CO)(I) with Na/Pb alloy and characterized crystallographically. Further reduction of the perfluorocarbene ligand with KC8 to give a perfluoroallene complex could be achieved.1 Similarly the corresponding compound Ir[=C(CF3)(CF2CF3]Cp*(CO) can been prepared and characterized crystallographically.2 It undergoes reduction to give a more diverse series of products, including the hexafluoro-2-butyne complex Ir(CF3C?CCF3)Cp*(CO) and the tetrafluorobutatriene complex Ir(CF2=C=C=CF2)Cp*(CO), the PMe3 analogue of which we have already reported.3 Efforts to extend this methodology to other members of group 9 and to group 10 are underway. Following our initial discovery of methodology to make the first examples of complexes containing CF as a terminal ligand,4 we have now extended this to the synthesis of the full series of group 6 complexes M(Cp#)(CO)2(CF).5 Chemical reactivity and DFT studies of these novel compounds are underway. Efforts to prepare other CF complexes will be guided by the isoelectronic relationship between terminal CF and NO ligands. (1) Yuan, J.; Hughes, R. P.; Rheingold, A. L., Eur. J. Inorg. Chem. 2007, 4723-4725. (2) Yuan, J.; Hughes, R. P., unpublished observations. (3) Hughes, R. P.; Laritchev, R. B.; Zakharov, L. N.; Rheingold, A. L., J. Am. Chem. Soc. 2004, 126, 2308-2309. (4) Huang, H.; Hughes, R. P.; Landis, C. R.; Rheingold, A. L., J. Am. Chem. Soc. 2006, 128, 7454-7455. (5) Huang, H.; Hughes, R. P., unpublished observations.
