Research On Late-Transition-Metal-Catalyzed C-C And C-X Bonds Formation Reactions

The transition-metal-catalyzed coupling reaction for the formation of carbon-car bon or carbon-heteroatom bonds has rapidly become a hot topic in organic synthesis in recent years. Moreover, environmentally friendly, atom-economical and green-chemistry can be realized by constructing the "transition metal catalyzed" coupling reaction of C-C and C-X bond. In this thesis, we used an efficient method which takes the late-transition-metal Re, Ni, Au as catalysts to develope the synthesis of heterocyclic compounds. The main points of this thesis are outlined as follows:Part1. Rhenium-catalyzed reaction for amination of alcohols.The transition metal mediated hydrogen transfer reaction has been reported. However, the Rhenium-catalyzed hydrogen transfer reaction for amination of alcohols is rarely developed. We developed a high-valent Rhenium-catalyzed hydrogen transfer reaction for amination of alcohols under the presence of CO. The reaction method is simple, can be carried out under mild conditions and gives an excellent yields. This method is a powerful tool for direct construction of C-N bonds from the cheap and easily available alcohols.Part2. Nickel-catalyzed [2+2] cycloaddition reaction of complex ketenes with simple alkynes for the construction of cyclobutene compounds.The structure of cyclobutene is important for versatile transformations of natural products and biologically active compounds. With [Ni(cod)2] and PCy3as the Catalytic system, the [2+2] cycloaddition of enones bearing a substituent group at the β-position with simple alkynes occurs to give cyclobutenes in one step. The method has the advantage of easy manipulation and mild reaction conditions. It provides an easy access to Polysubstituted cyclobutene compounds in high yields with a broad reaction scope.Part3. Gold-catalyzed cascade C-C and C-N bond formation:synthesis of polysubstituted pyrroles.Pyrrole is the important structural unit of heteroaromatic systems. Such as polysubstituted pyrroles present privileged skeletons frequently existed in a broad range of natural products and biologically important molecules and also as the key intermediates for the synthesis of functional materials. We described the synthesis of polysubstituted pyrroles with a series of nitroolefins by using [(PPh3)AuCl]/AgOTf as catalyst. The main advantages of the present synthetic protocol are that a mild, high yield, easy reaction and given in one step. Our method enriched the synthesis methods of polysubstituted pyrrole compounds and the application of catalytic role of Gold(I) in modern organic synthesis.