Synthesis Of Group-IV Metal Complexes Supported By Amide Ligands And Their Catalytic Behavior For Alkyne Hydroamination

The thesis mainly focused on the synthesis of group-IV metal complexes supported by amide ligands and their catalytic behavior for alkyne hydroamination. It's composed of following two parts.Firstly, eight different titanium and zirconium complexes were synthesized. They are Ti₂(bppda)₃(NMe₂)₂·3THF (1),Ti₂(bppda)₃(NEt₂)₂·3THF (2),Ti(bppda)₂ (3),Ti(bppda)(NPh) (4), Ti(p-toslopdi)(NEt₂)₂ (5),Ti(bph)(NMe₂)₂ (6),Ti (bppda)(N tBu)(Py) (7),Zr(bppda)₂·4THF (8), (H₂bppda=N,N'-bis(2-pyrrylmethylidene)-1,2-phenylenedia- mine; p-toslopdi=1,2-bis(p-toluenesulphonylamido)benzene; H₂bph=bis-(pyrrol-2-ylme- thylene)hydrazine). All these complexes were well characterized by elemental analysis and NMR spectroscopy. The molecular structures of complexes 1, 3, 5 were further determined by X-ray diffraction. Two ligands bridged binuclear titanium complexes of Ti2(bppda)3(NMe2)2?3THF (1) and Ti2(bppda)3(NEt2)2?3THF (2) were firstly synthesized and well characterized, and these titanium molecular structures were novel.Secondly, after these complexes were synthesized, their catalytic activity to the alkyne hydroamination reaction was also investigated. It's interesting to find that complex 1 could be used in the intermolecular hydroamination reaction of alkynes. With this catalyst, 1-hexyne which is an unsymmetrically terminal alkyne can be hydroaminated by both primary aromatic and aliphatic amine.. The resulting imines can be reduced to secondary amines. Compared with the traditional titanium catalyst loading of 10 mol%, the alkyne hydroamination could be performed at 80°C in toluene for 12 h in the presence of 5 mol% complex 1. In addition, the reaction occurs with high regioselectivity (>99:1) and preferring the Markownikow products. In summary, this kind of ligand bridged binuclear titanium complexes Ti2(bppda)3(NMe2)2?3THF (1) catalyzed hydroamination reaction was firstly reported by our research group. Furthermore, the catalytic behavior of complexes 6 and 7 for hydroamination of terminal alkyne and arylamines were also investigated, and the Markownikow products were preferred in the reaction of 1-hexyne with amine.