Synthesis of novel zwitterionic palladium complexes and study for their feasibility as recyclable catalyst system in Suzuki-Miyaura coupling

• Main Authors: Tzeng,Ru-Jiun, 曾如君
• Other Authors: Lee, Hon Man
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/30484075225522837259

碩士 === 國立彰化師範大學 === 化學系 === 104 === An efficient recyclable catalyst system for Suzuki-Miyaura coupling reactions in water was developed based on the zwitterionic palladium complex 2. The structure of 2 was established by X-ray crystallography. TEM studies revealed the involvement of palladium nanoparticles in the catalytic reaction. The use of excess n-tetrabutylammonium bromide (TBAB) as an additive was essential for their stabilization in water. Significantly, a phase separation was observed after several catalytic runs and the added TBAB became an ionic liquid supporting the palladium nanoparticles involved. Further TEM studies revealed the formation of palladium nanocubes in the TBAB layer. The formation such nanostructures could be explained by the production of KBr from the catalytic reaction serving as a capping agent. Recycling of the catalyst was allowed and up to nine consecutive catalytic runs could be achieved without significant loss of activity. In the practical aspects, the recyclable catalyst system allowed the use of unreactive aryl chlorides as substrates, the change of substrates between catalytic runs, manipulation of the reactions in air, and upscaling of the catalytic reaction.