101834-75-7Relevant academic research and scientific papers
Carbon-carbon bond formation on multisite-bound unsaturated ligands: Synthesis of μ2-η2-allenyl complexes via carbene addition to the binuclear acetylides Ru2(CO)6(μ2-η 2-C≡CR)(μ-PPh2)
Nucciarone, Donato,Taylor, Nicholas J.,Carty, Arthur J.
, p. 1179 - 1187 (2008/10/08)
Reaction of Ru2(CO)6(μ2-η 2-C≡CPh)(μ-PPh2) with N2CR2 (R = H, CH3, C6H5) results in formation of Ru2(CO)6(μ2-η2-R 2C=C=CPh)(μ-PPh2) (3a-c) in moderate to good yields. Compounds 3a-c have been fully characterized by infrared and 1H and 31P NMR spectroscopy as well as elemental analyses. A complete, single-crystal, X-ray diffraction study of 3c shows attack has occurred at the α-carbon atom of the acetylide (with respect to the ruthenium atom) resulting in formation of a σ,π-bound allenyl fragment. Complex 3c crystallizes in the triclinic space group P1 with cell constants a = 9.626 (1), b = 19.770 (3), c = 21.294 (2) A?, α = 119.18 (1)°, β = 100.28 (1)°, γ = 91.13 (1)°, and Z = 4. With use of 5767 independent reflections (I ≥ 3σ(I)) the structure was solved via the heavy-atom method and refined to R = 0.037 and Rw = 0.045. Solution NMR studies of 3a and 3b reveal rapid interchange of the R groups. A mechanism is proposed whereby exchange of the R groups occurs via a zwitterionic transition state involving rotation about the methylene carbon-sp carbon double bond.
