143063-90-5Relevant academic research and scientific papers
Half-open-titanocene chemistry: Coupling reactions of pentadienyl ligands with carbon-nitrogen and carbon-oxygen multiple bonds
Waldman, Thomas E.,Wilson, Anne M.,Rheingold, Arnold L.,Melendez, Enrique,Ernst, Richard D.
, p. 3201 - 3209 (2008/10/08)
The reactions of Ti(C5H5)(2,4-C7H11)(PEt3) (C7H11 = dimethylpentadienyl) with imines, ketones, and aryl isocyanides have been studied. In each case, the PEt3 ligand is lost. In the reaction with benzylidenemethylamine, spectroscopic data indicate that coupling of the imine with one end of the 2,4-C7H11 ligand has occurred. With acetone or 3-pentanone, 2 equiv is incorporated, leading to couplings with each end of the open dienyl ligand. A single-crystal X-ray diffraction study has been carried out for the latter. The space group is P21/c with a = 11.467 (3) ?, b = 7.647 (2) ?, c = 23.981 (7) ?, β = 92.11 (3)°, and V = 2101.3 ?3 for Z = 4. The structure was refined to discrepancy indices of R = 0.042 and Rw = 0.042 and revealed σ-allyl coordination as well as evidence for π-alkoxide donation. The reactions with RNC (R = C6H5, p-CH3C6H4, p-C2H5C6H4) were found to lead to the incorporation of 4 equiv of RNC. In each case, two of the isocyanides have, with the pentadienyl ligand, formed a coordinated diazabutadiene ligand and a seven-carbon-atom ring, while the other two have formed an unusual indole which is attached to the former pentadienyl ligand and to an amide which is coordinated to the metal center. For the p-C2H5C6H4NC product, the space group is P1 with a = 10.858 (11) ?, b = 11.103 (5) ?, c = 17.552 (8) ?, α = 90.35 (3)°, β = 96.80 (3)°, γ = 104.28 (6)°, and V = 2034.8 ?3 for Z = 2. The structure was refined to discrepancy indices R = 0.057 and Rw = 0.059.
