Nano Transition Metal-catalyzed Carbon - Carbon Bond Formation Reaction

Transition metals-catalyzed Heck and Sonogashira coupling reactions are some important methods for the formation of carbon-carbon bonds. Recently, many kinds of catalysts and ligands have been developed for these reactions by the synthetic scientists. The contents of this dissertation mainly discussed that PdCo bimetallic hollow nanospheres and Co nanspheres catalyst the above-mentioned reactions. The main contents are just as follows:1. An highly efficient PdCo bimetallic hollow nanospheres catalytic system was developed for the Sonogashira couplings reaction. In order to promote the catalytic activity of PdCo, CuI and PPh3 were used respectively as the associated catalyst and the ligand in the Sonogashira reaction. The tranditional organic solvents were replaced by water. It is indicated that a number of ArⅩ(Ⅹ=Ⅰand Br,) were coupled with olefins efficiently and selectively to afford the corresponding unsymmetric terminal alkynes with good to excellent yields. Furthermore, the operation of the experiment was simple, and the catalyst can be recovered. In agreement with the law of green chemistry, this research will own a promising future of application.2. An efficient catalytic system using PdCo bimetallic hollow nanospheres for the Heck-type reaction was developed. In the presence of PdCo bimetallic hollow nanospheres, the coupling of aryl iodides or the activated aryl bromine with olefms was carried out efficiently and selectively to afford the corresponding ternal olefins with moderate to good yields.3. Cobalt metallic hollow nanosphere was applied to catalyze Heck reaction. In the presence of Co hollow nanosphere, aryl iodides and the activated aryl bromine coupled with olefins was conducted smoothly with moderate to good yields in NMP. In this catalytic system, the Cobalt catalyst does not need any ligand, and can be recovered to be used for more than three times.