Studies On The Heck Reaction Catalyzed By Resin Supported Palladium Complex And The Ullmann Reaction In The Aqueous System

C（sp²）-C and C （sp²）-heteroatom coupling reaction catalyzed by transitional metal has become an indispensably key method in organic synthesis, widely used in the synthesis of a variety of natural, medical and agricultural products. However, the development of new catalysts of coupling reaction and the green synthesis methods are still greatly interested as environmental concerns. Therefore, some problem on this field was discussed on this paper, and the main contents and results were as follows:1. The resin supported palladium catalyst was prepared and used in the Heck coupling reaction of aryl halide. 4-Aminopyridine resin supported palladium complex （4-APR-Pd （II））, piperazine resin supported palladium complex （PM-Pd（ II）） and 2-methylpiperazine resin supported palladium complex were prepared by PdCl₂ reacting with 4-aminopyridine resin, piperazine resin and 2-methylpiperazine resin, respectively. These three kinds of catalysts were tested on the Heck reaction, and the effects of solvents, bases, temperature and the amount of catalysts were discussed. Excellent catalytic properties and reusability was obtained for the reaction of iodobenzene in air atmosphere without the presence of phosphine ligand, and good results were also obtained for the substrates of bromobenzene and the activated aryl chlorides.2. The application of solid base in the Heck reaction of heteroaryl halides and olefins was studied. Heck arylation of 3-bromoquinoline and n-butyl acrylate was catalyzed by Pd（OAc）₂ at low amount, using D301 or D201×4 resin as solid base, NMP or NMP/H₂O as solvent, and high yields was obtained. It was also found that D301 resin was a reusable base and could be regenerated and recycled in the reaction. The olefination of heteroaryl halides such as bromopyridine, bromoquinoline and bromothiophene prepared the corresponding products in good yields.3. And then, the Ullmann coupling reaction of heteroaryl compounds catalyzed by Pd/C catalysts was investigated. 3, 3’-dithiophene was obtained with high yield in the reductive coupling reaction of 3-bromothiophene in the system of H₂O-alcohol, using Pd/C as catalysts. The influences of alcohol, base and the amount of the catalysts were discussed. The different substrates were also studied, and a variety of heteroaryl halides can be used to prepare di-aryl compounds with high yield without the addition of phase-transfer catalysts, and Pd/C catalyst can be reused. 2, 2’-diquinoline and 5, 5’-dibromo-2, 2’-dithiophene were prepared with high yields by the oxidative coupling of quinoline and 2-bromothiophene respectively, using the mixed solvent of H₂O and organic solvent. The catalysts can be regenerated and reused for several times, with the advantage of low cost and small pressure on the environment.