Imido and amido titanium complexes that contain a [OSSO]-type bis(phenolato) ligand: Synthesis, structures, and hydroamination catalysis

Abstract

Salt metathesis reaction of the imido complex [Ti(NR)-Cl 2(NC5H5)3] (R = tBu, C 6H3iPr2-2,6) with 1 equiv. of the lithium salt of the corresponding [OSSO]-type bis(phenol) [edtbpH2: (HOC 6H2-tBu2-4,6)2(SCH 2CH2S); rac-(cydtbp)H2: (HOC6H 2-tBu2-4,6)2(S2C6H 10-1,2)] afforded imido titanium complexes [Ti(edtbp)(NtBu)(NC 5H5)] (1), [Ti(edtbp)(NC6H3-iPr 2-2,6)(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, 2009.