Synthesis And Application Of Supported Gold (?) Catalyst For Cyclization Reactions

Gold catalysis, owing to its unique catalytic activity and selectivity in the organic reactions, has become a rapidly developing topic in the field of organometallic chemistry. Immobilization of the gold(?) complexes onto solid supports would facilitate the recovery and reuse of these precious catalysts in organic synthesis. In this thesis, we have focused on the synthesis of heterogeneous gold(?) catalysts, which including the following three parts:1) FDU-15 supported gold(?) catalyst FDU-(p-CF3Ph)2PAuCl has been successfully synthesized and characterized. The catalyst exhibits good catalytic activity in the cyclization of ?-hydroxy alkynone. It has been found that the electronic effects of the substituents on the benzene ring of substrates have influenced the reaction activities, while the position of the substituents on the benzene ring of substrates have little influence on the reaction activities. Under the optimal reaction conditions, eleven new ?-aryl-?-pyrone compounds have been synthesized for the first time. Moreover, the catalyst is also applicable to the cyclization of 3-alkynyl-1,2-diol. The catalyst can be recycled and reused for five times without obviously loss of catalytic activity.2) SBA-15 supported gold(?) catalyst SBA-PPh2AuCl has been developed and characterized. The catalyst exhibits good catalytic activity in hydroamination of olefins. It has been shown that the reaction activities have been influenced by the steric hindrance on nitrogen atom and electronic effects of substituents on the benzene sulfonamides. The catalytic activity was gradually decreased with the increased recycle times under the reaction temperature of 85?. In addition, the electrophilic addition of 2-(1-alkynyl)-2-alken-1-ones can be carried out at room temperature. The catalyst can reused six times and various substrates are well tolerated. More importantly, the reaction was significantly promoted by the synergetic effect of the support. The research results indicate that the stability of catalyst was affected by reaction temperature.3) SBA-15 supported chiral gold(?) catalyst SBA-P*AuCl has been synthesized and characterized. The catalyst has well performed in asymmetric gold catalyzed cycloaddition reaction of 2-(1-alkynyl)-alk-2-en-1-ones with nitrones. The catalyst can be reused six times without loss of catalytic activity.