trans- or cis-2,3-Bis(hydroxymethyl)methylenecyclopropanes react with [Fe2(CO)9] to produce tricarbonyl-η 4-[3-methylene-endo-4-vinyldihydrofuran-2(3H)-one]iron(0) and tetracarbonyl-η 2-[3-methylene-exo-4-vinyldihydro-furan-2(3H)-one]iron(0). The structural identities of these two complexes have been established by the analysis of single-crystal X-ray data recorded on a four-circle diffractometer. The tricarbonyl complex is triclinic, space group P1, with a = 7.745(5), b = 6.787(3), c = 9.873(4) Å, α = 96.46(3), β = 86.79(4), γ = 94.05(4)°, and Z = 2. Full-matrix least-squares refinement using 1 435 independent observed reflections has converged to R = 0.029, Rw 0.031. The metal co-ordination geometry approximates to that of a square pyramid with the alkene fragments in cis-equatorial positions. Four molecules of the tetracarbonyl crystailise in the monoclinic space group P21/a with a = 12.419(4), b = 6.527(1), c = 15.321 (4) Å, β = 91.21 (2)°. The model has been refined to R 0.041, Rw 0.044 for 1 679 reflections. In this complex the Fe(CO)4 moiety is attached to the opposite side of the organic fragment via the rigid alkene function, which occupies one equatorial site of a trigonal bipyramidal co-ordination geometry. Analogous reactions of trans-2,3-bis(dideuteriohydroxymethyl)methylenecyclopropane and trans-2,3-dideuterio-2,3- bis(hydroxymethyl)methylenecyclopropane with [Fe2(CO)9] yield analogous deuteriated iron complexes with no deutcrium scrambling. 1H and 13C N.m.r. spectra are reported and a plausible mechanism is presented.
|Number of pages||9|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|Publication status||Published - 1976|
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