Reactivity of rhodium hydrido and silyl complexes towards 1, 1-difluoroallene

The reaction of rhodium(I) complexes [Rh(E)(PEt3)(3)] (E = H (2), Si(OEt)(3) (4)) with 1,1-difluoroallene provides the rhodium (III) complexes [Rh(eta(2)-CH2=C=CF2)(eta(3)-CH2C(E)CF2)(PEt3)(2)] (E = H (3), Si(OEt)(3) (5)). The conversions involve the coordination of one equivalent of difluoroallene to form a rhodiumcyclopropane and the insertion of a second equivalent into the Rh -E bond. X-ray crystallography as well as DFT calculations support the suggested structures as well as the arrangement of the fluorinated ligands. In contrast, when [Rh{Si(OEt)(3)}(PEt3)(3)] (4) reacted with hexafluoropropene, only the coordination of the fluorinated olefin was observed resulting in the formation of [Rh(CF2CFCF3){Si(OEt)(3)}(PEt3)(2)] (6).