Studies On Synthesis, Characterization And Asmmeric Catalytic Performance Of Metallic Catalysts Based On Chiral Binaphthoxy

Chirality, one of the basic natural properties, is present through the world. Over150years ago, one of the organic chemistry pioneer, Louis Pasteur, predicted "The univers is chiral,……the univers was dominated by asymmetry." If one thing can not overlap with their image, it has the chirality. This is like people's hands, which the left hand is the image of the right hand, but they cann't overlapped. Chirality is involved with the life. In nature, most of the living molecule is chiral, for example, DNA, amino acid, protein, sugar, hormones etc. The natural sugar is a D-type structure, the amino acid is L-shaped structure, the helical structure of proteins and DNA are right-handed structure. Chirality is a natural properity which the people living on. Enzyme playing a different physiological role in the human body is chiral. The physical and chemical processes of the human body are in highly asymmetric environment, so it is different for the physical activity of two enatiomers in the human body.Polyolefin has been one of the widely used synthetic polymers in our daily life. It is meanful for the development of the chiral material to obtain chiral polymers. Metallocene catalysts are one type of the best catalysts to sythesis high-performance polymers. So we sythesized a series of novel chiral metallocene catalysts and studied their properity in polymerization. On the other hand, The using of chiral transition metal catalysts to provide enantiomerically enriched products is of central importance in modern synthetic chemistry and a core technology in the pharmaceutical, agrochemical, and fine chemical industries. A lot of efficient transition metal catalysts containing various phosphines as ligands promote the development of asymmetric hydrogenation. The self-supported asymmetric hydrogenation catalysts are a recently reported promising immobilization strategy for homogeneous catalysts, in which some problems of homogeneous catalysts such as difficult recovery of expensive chiral catalysts, catalysts instability and metal contaminants leached from the catalysts in the products were not only solved, the resulted catalysts but also show retentive enantioselectivity and similar efficiency in the catalysis. As a result of our interest in the developing self-supported catalyst in asymmetric hydrogenation, we synthesized a series of novel phosphate RhⅠ-catalysts and studied their properity in asymmetric hydrogenation of olefin derivatives.Conclusions are summarized as follows:In Chapter Two, we report herein a series of novel chiral self-supported RhⅠ-catalysts containing substituted binaphthyl phosphite-based ligands with1,3,5-tri(4-hydroxyphenyl)-benzene as the linker. These ligands were characterized by1H NMR,13C NMR,31P NMR and IR analysis. The supported catalysts were synthesized by assembly of RhⅠ metal ion with the ligands. These catalysts were characterized by elemental analysis, IR, X-ray powder difficution and SEM analysis. The results showed that the micrometersized particles are amorphous. The ratio of the monophosphite units to that of RhⅠ center was calculated to be closely equal to two.In Chapter Three, we developed the self-supported catalysts, which were synthesized in chapter two, in asymmetric hydrogenation of olefin derivatives. The self-supported catalysts displayed similar catalytic performance for the asymmetric hydrogenation compared to their corresponding monophosphite-RhⅠ catalysts. The substituents on the BINOL skeleton in the3,3'-and6,6'-have great effect on the product conversion and ee values. The6,6'-6,6'-dimethyl-BINOL-derived phosphines exhibited high activity and enantioselectivity in the asymmetric hydrogenations of Dimethyl Itaconate, α-acetamidoacrylate, α-acetamido-β-phenylacrylate, and enamide. The chiral self-supported catalysts were easily recovered from the reaction mixture and were reusable for five consecutive runs without loss in ee (95-98%).In Chapter Four, Two new chiral ligands, were synthesized by reaction of (R)-3,3'-dilithium-2,2'-bismethoxy-1,1-bisnaphthalene with2,3,4,5-tetramethyl-2-cyclopentenone at room temperature. Treatment of the free ligands with butyllithium and Me3SiCl first, and subsequently with TiCl4(2and1equiv for1and2, respectively) afforded a binuclear complex and a mononuclear complex in moderate yields. The binuclear complex and mononuclear complex were further converted into constrained geometry complexes by treatment with BBr3. The free ligands were characterized by1H NMR,13C NMR and high resolution mass spectroscopy, and the new titanium complexes were characterized by1H NMR,13C NMR and elemental analyses. Molecular structures of three new titanium complexes were determined by single-crystal X-ray diffraction analysis. All complexes have a pseudo-octahedral coordination environment and adopt a three-legged piano stool geometry around the titanium atom in their solid state structures.In Chapter Five, we developed the chiral constrained geometry titanium complexes in olefin polymerization. When activated with Al'Bu3and Ph3CB(C6F5)4, the chiral complexes show moderate catalytic activities for propylene,1-hexene, and5-ethylidene-2-norbornene (ENB) polymerization and ethylene/1-hexene copolymerization. The polymers produced by the chiral binuclear catalyst system from the1-hexene, and ENB polymerization and ethylene/1-hexene copolymerization with high comonomer contents exhibit optical activity.