Asymmetric Catalytic Silylation Reaction And The Synthesis,Application Of Metal Organic Frameworks

Asymmetric catalysis is one of the common mothods for obtaining the chiral compounds and chiral intermediates. There are many advantages for asymmetric catalysis. Such as, the reaction is efficient and economic as well as the reaction condition is mild. It has good stereo selectivity and the two isomers are equally easy to produce. In addition, the prochiral substrate is widely used. The development of the catalyst with good selectivity and broad application is the pursuit of the most chemists. In recent years, the use of chiral nitrogen heterocyclic carbene (NHC) as ligand in asymmetric catalysis has been rapidly developed. Compared with the previous phosphine ligands, it not only has good bonding ability with metal, but also has more structure types. Flexible steric hindrance, electronic effect and stability to heat, water, air as well as the advantages of easy synthesis make it better than phosphorus ligands in the catalytic activity and the application range.In addition, in recent years, the development of asymmetric catalyst becomes more diversified and the choice for chiral source is more diverse. [2.2] paracyclophane derivative is one of typical planar chiral ligands similar to ferrocene. It has been paid more and more attention for their application in asymmetric catalysis since the end of the last century. Besides changing the electronic effect and steric effects, one can develop ligands with special spatial configuration and introduce different coordinated atoms in one ligand. In addition, the development of dual chiral ligands even multi chiral ligands is a hot research topic.Our group has been committed to the development and application of N-heterocyclic carbene catalysts based on [2.2] paracyclephane. And these catalysts are successfully applied to the rhodium catalyzed asymmetric addition of arylboronic acid to aromatic aldehydes and copper catalyzed asymmteric addition of boron reagents to a, β-unsaturated ketones and esters. A preliminary study on the application of the N-heterocyclic carbene in organic catalysis has been completed. But the development and modification of [2.2]paracyclephane ligands especially dual chiral ligands, as well as the expansion of catalysis scope still need to father study.In addition, metal organic framework is another research direction for us. Metal organic frameworks is an emerging class of polymer material with periodic one dimensional, two dimensional, three dimensional structure, which are constructed from metal containing nodes (also known as secondary building units, or SBUs) and organic linkers. Due to their structural and functional tunability as well as broad application prospects, the area of MOFs has attracted more and more attention of researchers. In the past two decades, this field has experienced explosive growth and change. The applications in the field of gas storage and separation, magnetism, fluorescence, catalysis and molecular recognition are constantly developed. Therefore, the thesis developed the following innovative researchPart 1 Synthesis and application of [2.2]paracyclophane-based N-Heterocyclic Carbene precursors. This part mainly includes the following contents.Chapter 1, research backgroundIntroduce the research progress of planar chiral [2.2] paracyclephane derivatives and N-heterocyclic carbene ligands in the field of asymmetric catalysis.Chapter 2, the synthesis of dual chiral triazolium carbene precursor based on [2.2] paracyclephaneDesign and synthesis of fluorinated and formyl amine substituted dual chiral triazolium ligands base on transannular electronic effects of [2.2] paracyclephane. And the problems encountered in synthesis are also discussed.Chapter 3, the application of the dual chiral triazolium ligands in copper catalyzed asymmetric silylation reactionThe excellent catalytic effect of dual chiral triazolium ligands have been proved in asymmetric boration reaction of chalcone derivatives. Base on the requirement to extended application scope, the fluorinated dual chiral triazolium ligand was applied to the asymmetric silylation of N-sulfonylimine for the first time. To our delight, it achieved very high reactivity and satisfactory selectivity. In addition, we have studied the influence of steric and electronic effects of the ligands. Through a series of screening of base, solvent, temperature and ligands, this reaction demonstrated good catalytic effect for 20 substrates under the optimal conditions.Chapter 4, asymmetric a-silylation of N-sulfonylimines catalyzed by fluorinated dual chiral triazolium salt catalystBesides metal catalysis, organic catalysis is another hot research topic for N-heterocyclic carbene, especially for triazolium carbene. Asymmetric β-boration of chalcone derivatives by N-heterocyclic carbene catslyst has been preliminary studied in our group. It is proved that these ligands have good catalytic activity. As an extension of silylation catalyzed by a carbene-metal catalyst, the silylation of N-sulfonylimine catalyzed by a carbene catalyst was also studied. The result is not very good, the yield dropped sharply and the selective is also decreased in different degrees.Chapter 5, synthesis and structural characterization of helical chiral bis-imidazolinium salt ligand based on [2.2] paracyclophaneDesign and synthesis a helical-chiral dual imidazolinium salt derivative based on [2.2] paracyclophane. And its structure was characterized. By means of x-ray single crystal diffraction, the absolute configuration and the helical-chiral were determined. But because of the steric hindrance and the degree of distortion of the ligand, the preparation of ligands is not easy and the product is not stable. We have proved that one of the imidazolinium rings is easy to open. Due to the instability of the structure, the preparation of complex and its catalysis application is not ideal. But the novelty of its structure is a highlight.Part 2 Synthesis and properties of Metal-Organic Frameworks. This part mainly includes the following contents.Chapter 6, introduction of metal organic frameworkIntroduce the synthesis methods, influencing factors, and related properties of metal organic framework.Chapter 7, the synthesis and properties of multi-carboxylate ligands and their metal-organic frameworkDesign and synthesis of double carboxyl imidazolium salt ligand based on [2.2] paracyclephane and large skeleton four carboxylic acid ligands. Prepare metal organic frameworks by the two ligands. Finally, a novel structure of europium-organic anion framework was successfully obtained. Through the exchange of [H2N(CH3)2]+in channels with metal ions, a new fluorescence probe was developed.Chapter 8, Anion-controlled formation of silver lamella frameworks based on in situ ligand reactionDesign and synthesis of a flexible nitrogen and sulfur based ligand. Two silver lamella frameworks are prepared by using this ligand. But by crystal resolution, we discovered the real ligand is 2-thiol pyridine. Through a series of characterization and comparable experiment, the occurrence of in situ ligand reaction and the dual role silver ions played in the formation of framework were proved. In addition, this example also shows the effect of anion-controlled on framework structure.