Imido and Amido Titanium Complexes that Contain a [OSSO]-Type Bis(phenolato) Ligand: Synthesis, Structures, and Hydroamination Catalysis

Salt metathesis reaction of the imido complex [Ti(NR)Cl2(NC5H5)3] (R = tBu, C6H3iPr2-2,6) with 1 equiv. of the lithium salt of the corresponding [OSSO]-type bis(phenol) [edtbpH2: (HOC6H2-tBu2-4,6)2(SCH2CH2S); rac-(cydtbp)H2: (HOC6H2-tBu2-4,6)2(S2C6H10-1,2)] afforded imido titanium complexes [Ti(edtbp)(NtBu)(NC5H5)] (1), [Ti(edtbp)(NC6H3iPr2-2,6)(NC5H5)] (2), and [Ti{rac-(cydtbp)}(NtBu)(NC5H5)] (3). The bis(dimethylamido)titanium complex [Ti(edtbp)(NMe2)2] (4) was synthesized by protonolysis of [Ti(NMe2)4] with bis(phenol) edtbpH2. Reaction of [Ti(NMe2)Cl3] with the lithium salt of the bis(phenol) gave the chloro dimethylamido complex [Ti(edtbp)(NMe2)Cl] (5) in high yield. All complexes were characterized by NMR spectroscopy and elemental analysis. Additionally, complexes 1 and 5 were studied by X-ray diffraction analysis. Imido titanium complex 1 shows moderate activity in the intramolecular hydroamination reaction of 5-phenylpent-4-ynylamine. Complexes 1–3 catalyze the intramolecular hydroamination of aminoalkenes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)