| Transition metal-catalyzed coupling reactions play an important role in organic synthesis, especially in the assembly of heterocycles. Certain metal catalysts such as Pd, Au, Ag, Rh, Ni and Cu have been intensely investigated. Among them, Cu has been outstanding due to its high efficiency, low cost and low-toxicity. The last decade has witnessed the booming development in Cu-catalyzed coupling reactions with the improvement in reaction conditions, especially the introduction of effective ligands. Nowdays, one of the most important development trends has been the application of copper-catalyzed coupling in the assembly of various heterocycles via cascade process.The dissertation is focused on the synthesis of indole-incorporated derivatives and2H-1,4-benzoxazin-3-(4H)-ones via novel Cu-catalyzed cascade reactions. Three chapters are included.Chapter1(the perface) briefly reviews the development of copper-catalyzed coupling reactions and the application of copper-catalyzed cascade reactions in the assembly of heterocycles.Chapter2studies the synthesis of novel poly cyclic indole derivatives via copper(1)-catalyzed domino intramolecular cyclization. Three polycyclic indoles (benzo [5,6][1,3]oxazino[3,2-a] indol-12-ones, indolo [2,1-b] quinazolin-12-ones and thiazino[3,2-a]indol-12-one) were efficiently synthesized from readily available materials via a mild and facile Cu2O-catalyzed domino intramolecular C-N/C-Y (Y=O, N, S) coupling process. This method was particularly practical since imidazoindolones could be synthesized efficiently under mild conditions, and the polycyclic indole derivatives could be successfully synthesized in large-scale.Chapter3describes the synthesis of2H-1,4-benzoxazin-3-(4H)-one derivatives via the copper(I)-catalyzed intermolecular condensation/intramolecular C-N coupling process. A variety of2H-1,4-benzoxazin-3-(4H)-ones have been prepared efficiently and conveniently via the simple Cu-catalyzed one-pot protocol. Our method possesses various advantages such as the employment of readily available materials, mild reaction conditions and wide functional group tolerance. The method introduced directly and conveniently various substituents on the4-position of the products by simply varying the starting amines. More complex compounds could also be elaborated by using this strategy. |
