Facile Carbon–Fluorine Bond Activation and Subsequent Functionalisation of 1,1‐Difluoroethylene and Tetrafluoroethylene Promoted by Adjacent Metal Centres |
| |
| Authors: | Michael E. Slaney D. Jason Anderson Dusan Ristic‐Petrovic Dr. Robert McDonald Prof. Dr. Martin Cowie |
| |
| Affiliation: | 1. Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2 (Canada);2. Department of Chemistry and X‐Ray Crystallography Laboratory, University of Alberta, Edmonton, AB T6G 2G2 (Canada) |
| |
| Abstract: | The bridging fluoroolefin ligands in the complexes [Ir2(CH3)(CO)2(μ‐olefin)(dppm)2][OTf] (olefin=tetrafluoroethylene, 1,1‐difluoroethylene; dppm=μ‐Ph2PCH2PPh2; OTf?=CF3SO3?) are susceptible to facile fluoride ion abstraction. Both fluoroolefin complexes react with trimethylsilyltriflate (Me3SiOTf) to give the corresponding fluorovinyl products by abstraction of a single fluoride ion. Although the trifluorovinyl ligand is bound to one metal, the monofluorovinyl group is bridging, bound to one metal through carbon and to the other metal through a dative bond from fluorine. Addition of two equivalents of Me3SiOTf to the tetrafluoroethylene‐bridged species gives the difluorovinylidene‐bridged product [Ir2(CH3)(OTf)(CO)2(μ‐OTf)(μ‐C?CF2)(dppm)2][OTf]. The 1,1‐difluoroethylene species is exceedingly reactive, reacting with water to give 2‐fluoropropene and [Ir2(CO)2(μ‐OH)(dppm)2][OTf] and with carbon monoxide to give [Ir2(CO)3(μ‐κ1:η2‐C?CCH3)(dppm)2][OTf] together with two equivalents of HF. The trifluorovinyl product [Ir2(κ1‐C2F3)(OTf)(CO)2(μ‐H)(μ‐CH2)(dppm)2][OTf], obtained through single C? F bond activation of the tetrafluoroethylene‐bridged complex, reacts with H2 to form trifluoroethylene, allowing the facile replacement of one fluorine in C2F4 with hydrogen. |
| |
| Keywords: | bridging ligands C?F activation fluorinated ligands fluorine |
|
|
