Research On The Carbon-Oxygen Coupling Reaction Catalyzed By Copper

Diaryl ethers exist widely in many natural products with biological activities. Now, they have significant application in agriculture, medicine, industry and polymer. In fact, many natural physiological active peptides contain diaryl ethers bridge, such as anti-HIV, K-13, phenothrin, anti-inflammatory drug naproxen. The method to build C-O is very important for synthesis of natural products, medicine, pesticide and so on. Therefore, it is one of important research topics for organic chemists.Ullmann reaction is widely used in organic chemistry and it is an effective method to form C-C, C-N, C-O and C-S bonds. Through Ullmann reaction we can generate aryl ethers, aromatic amines, aromatic thioethers, alkyl ethers, alkyl amines, alkyl thioethers.They compounds are important intermediates for the synthesis of many organic molecules, which are widely used in medicine, pesticides, dyes and organic conductor, semiconductor, etc. Herein, we summarized the synthetic methods of diaryl ethers in recent years and explored the reactions catalyzed by copper under ligands and no ligands. The main results are as follows.We synthesized a series of simple and easy N, O ligands-Betti base derivatives. Reports for Betti bases are mainly as chiral substrates and separation agent, while as ligands in catalytic C-O coupling reaction have not been reported. In this thesis, eight kinds of Betti base derivatives were synthesized. We use2-pyridine formaldehyde, β-naphthol and methylamine, morpholine, pyrrolidine, six hydrogen pyridine synthesized four new compounds. Their structures were confirmed by IR, NMR.We used the eight kinds of Betti base derivatives as ligands in the C-O coupling reaction catalyzed by CuI.1-(1-dimethylamino-2-pyridin-methyl)-2-naphthol was found to be the optimal ligand. We optimized the reaction conditions. Using DMSO as solvent and K2CO3as base, the reaction of Ullmann-type O-arylation with aryl iodide, activated aryl bromide and chloride and substituted phenol can proceed smoothly under low temperature with excellent yields. This catalyst is stable in air and can be reused for several times. The crystal structure of L5prepared in mixed solvent of ethyl acetate and ethanol was confirmed by X-ray single crystal diffraction.No ligand reaction can reduce the use of ligand, improve the economic benefit of reaction process, simplify the reaction, So we have attempted the C-O coupling reaction under no ligand catalyzed by copper. Under the condition of copper powder as catalyst, acetonitrile as the solvent, K2CO3as base, Tetra-butylammonium bromide(TBAB) as phase transfer catalyst, we obtained the coupling products with excellent yields. According to the experimental results, we further discussed the influence of electronic effect of the substrate on the yields and investigated the reusablitily of catalyst.