Hydro- and chloro-substituted silyl- and silyl-η1-amido-η5-tetramethylcyclopentadienyl titanium complexes

Chlorosilyl-cyclopentadienyl titanium precursors [Ti(η5-C5Me4SiMeXCl)Cl3] (X=H 2, Cl 3) were prepared by reaction of TiCl4 with the trimethylsilyl derivatives of the corresponding cyclopentadienes. Methylation of these compounds with MgClMe under appropriate conditions afforded the methyl complexes [Ti(η5-C5Me4SiMe2R)XMe2] (R=H, X=Cl 5, Me 6; R=X=Me 7). Reactions of 2 and 3 with two equivalents of LiNHtBu afforded the ansa-silyl-η-amido compounds [Ti{η5-C5Me4SiMeX(η1-NtBu)}Cl2] (X=H 8, Cl 9). Methylation of 8 gave [Ti{η5-C5Me4SiMeH(η1-NtBu)}Me2] 10. Complex 9 was also obtained by reaction of 8 with BCl3, whereas the same reaction using alternative chlorinating agents (TiCl4, HCl) resulted in deamidation to give 2, which was also converted into 3 by reaction with BCl3. All of the new compounds were characterized by NMR spectroscopy and the molecular structures of 2 and 4 were determined by X-ray diffraction methods.