Organicsilincon-Mediated Palladium Catalyzed Organic Transformations

The application of organosilicon compounds in organic synthesis reactions has received much attention in the past decades, which promoted the vigorous development of organic chemistry. The research work of this thesis has been focused on a series of organic synthesis reactions, especially the organosilicon compounds-mediated palladium catalyzed reaction. First of all, trimethylchlorosiiane was used as efficient reagent in the one-pot reaction through lateral sequential lithiation/silylation/condensation of N,N-isopropyl2,2-methyl benzamide. And a series of functional olefins with larger steric tertiary aromatic amides substituted was prepared in high yields. These functional olefins could be employed to the next transformation or possess as ligands or substrates in transition-metal catalyzed organic reactions. Subsequently, an efficient and simple method was established to detect the coordination or interaction between transition-metal salts and functional olefin-containing tertiary amides by fluorescence spectroscopy. These olefins showed relatively stronger fluorescence effect when mixed with palladium acetate. The third, a highly efficient catalytic protocol for the isomerization of substituted amide-derived olefins was demonstrated with HSi(OEt)3and [PdCl2(PPh3)2] as a catalytic system. The Z to E isomerization was carried out smoothly and resulted in geometrically pure substituted olefins. And then, with this hydrosilane-directed palladium-catalyzed isomerization process, it was further worked as a springboard to the hydrogenation of activated olefins or terminal olefins and the reductive decarbonylation of acyl chlorides in the presence of hydrosilanes. It is also found that the aromatic tertiary amides olefins compounds can be used as a ligand in the palladium-catalyzed Suzuki cross coupling reaction. Compared with previous palladium-catalyzed Suzuki reactions, this simple, efficient, and phosphine-free method does not require special work-up to the reaction system. At the last, a novel poly(methylhydrosiloxane) promoted palladium/bismuth catalyzed oxidative esterification reactions of primary benzylic alcohols was established in this work. This catalyst system has several advantages of high yields, ligand-free, direct use of air atmosphere as terminal oxidant, and the catalytic performance is high enough in this oxidation.