Preparation And Application Of Amino Acid And N-heterocyclic Carbene Ligands

Catalysis technology is the fundamental of modern chemical industry, and penetrating increasing broadly in crude oil refining, chemistry, polymer material, pharmaceutical, industry and environmental protection industry. It shows vital affection in these fields. Transition-metal-catalyzed cross-coupling reaction is an efficient tool for constructing C-C, C-N and C-O bonds in organic synthesis. Due to ligands play a key role in stabilizing and activating the central metal atom and fine-tuning the selectivity of transformation, intensive interests have been focused on the development of most effective ligands which improve catalyst performance. In this dissertation, according to the requirement of green chemistry and sustainable development, and in view of drawbacks in current transition-metal ligands, such as high reaction temperature, not environment benign, using toxic and complicated to prepare phosphine ligands, we focuse on researching environment-friendly, easy to synthesize ligands and preparing heterogeneous supported catalysts and their application in organic synthesis, developing certain applied value in industry.Using low cost, easy obtained and non-toxic proline as starting material, one fluorous amino acid ligand has been prepared, and also inspected its application in Cu-catalyzed Henry reaction, Pd-catalyzed Suzuki and Heck cross-coupling reactions. By utilizing fluorous-fluorous interactions, the palladium complex contains fluorous ligand was supported on fluorous silica gel, and its catalytic efficiency was investigated in Suzuki and Heck cross-coupling reactions. The observation and study showed supported Pd catalyst is not sensitive to water and air, it has good stability and catalytic activity, and easy to recycle and reuse through simple filtration and wash. The catalyst can be reused several times without significant loss of activity.Two NHC-Cu complexes have been prepared successfully. To investigate their activity in hydroxylation of aryl halides, KOH was chosen as-OH source to replace water sensitive and expensive CsOH, the desired products were obtained in good yields. A fluorous silica gel supported NHC-Pd catalyst was prepared and inspected its application in Suzuki and Heck cross-coupling reactions, the heterogeneous catalyst can be recycled and maintained good catalytic activity, In addition, one NHC-Cu complex supported on silica gel was prepared and utilized in Click reaction in water. Utilizing benzyl halides and sodium azide as the replacement of organic azides, good catalytic efficiency and recyclability of the catalyst was obtained.Amino acids as ligands can improve reaction efficiency significantly in C-H activation. Based on this point, and combine linear cyano directing group, C-H activation and functionalization on meta-selectivity of benzoic acid derivatives and phenol derivatives have been investigated. In addition, methylation on meta position was achieved in optimized conditions.