From Organic Azides through Titanium Triazenido Complexes to Titanium Imides
Manßen M., Weimer I., Adler C., Fischer M., Schmidtmann M., Beckhaus R.
The reactions of organic azides (RN3; R = 2,6-dimesitylphenyl, SiMe3) with bis(η5:η1-pentafulvene)titanium complexes 1 and titanium monopentafulvene complexes [Cp#Ti(η5:η1-pentafulvene)Cl] (5; #: R5 = H, Me) were investigated. For complexes 1, insertion of the γ-N atom of the azide into the Ti–Cexo bond results in the formation of titanium triazenido complexes 2 in good yields. Complexes 2 undergo subsequent rearrangements in solution to titanium imido complexes 3 and 4 through release of N2. Due to a haptotropic shift of the fulvene ligands, C–C coupling of the fulvenes occurs and leads to a new chelating cyclopentadienyl allyl system. By the use of the Lewis donor 4-chlorobenzonitrile these imido complexes are stabilized. Monopentafulvene complexes 5 directly generate chlorido-bridged titanium imido complexes 6 by release of N2 and the fulvene ligand. These new compounds were characterized by NMR spectroscopy and single-crystal XRD.