Synthesis of titanium complexes that contain triamido-amine ligands

We report the synthesis of a variety of titanium complexes that contain (Et(3)SiNCH(2)CH(2))(3)N, (C6F5NCH2CH2)(3)N, or (Me(3)SiNCH(2)CH(2)CH(2))(3)N Ligands. Complexes in the first category include [(Et(3)SiNCH(2)CH(2))(3)N]TiCl, [(Et(3)SiNCH(2)CH(2))(3)N]Ti(OTf), and [(Et(3)SiNCH(2)CH(2))(3)N]Ti-(t-Bu). Complexes in the second category include [(C6F5NCH2CH2)(3)N]TiX (X = Cl, Br, I, OTf) and [(C6F5NCH2CH2)(3)N]TiR (R = Me, Et). Complexes in the third category include [(Me(3)SiNCH(2)CH(2)CH(2))(3)N]TiCl and [(Me(3)SiNCH(2)CH(2)CH(2))(3)N]TiCH3. In an X-ray study [(Me(3)-SiNCH2CH2CH2)(3)N]TiCl was shown to contain a coordinated amino nitrogen and TiN2C3 rings that were puckered in a pseudocyclohexane chair form. The TiN2C3 rings are proposed to ''flip'' via dissociation of the amino nitrogen donor in the methyl complex, but the flipping rate is slow on the NMR time scale in [(Me(3)SiNCH(2)CH(2)CH(2))(3)N]TiCl as a consequence of the greater electrophilicity of the metal.