Study On Palladium-catalyzed Synthetic Methods Transformation Of Isocyanides Into Nitrogen-containing Heterocyclic Compounds

With the continuous development of the transition metal-catalyzed chemistry and synthetic organic chemistry in recent years, the method on the synthesis of nitrogen-containing heterocycles, through the reactions of isocyanides reacting with other synthons by utilizing transition metals particularly with palladium catalysts, has become a highly potential area for the development. As a kind of reactive molecule in organic synthesis, the structure and properties of isocyanides are similar with CO. The insertion reactions using isocyanides as C1 building blocks and the alternatives of CO have attracted much more attention in the past decade. This thesis starts from the construction of new C-C and C-N bonds, and we then mainly introduced the synthesis of valuable nitrogen heterocyclic compounds via palladium catalysis. The research work consists of the following two parts.In chapter two, by using N-benzoylsulfonamide as a directing group, we introduced the construction of 6-aminophenanthridines via pallidium-catalyzed activation of ortho aryl C-H bond of 2-aminobiaryls and then isocyanide insertion into the C-Pd bond. Meanwhile, we could perform the debutylation of the obtained products to afford 6-aminophenanthridine(6APs), an effective inhibitor of yeast prions, which has been successfully applied as the drugs for against mammalian prions. Moreover, upon a literature investigation, the skeleton of 6-aminophenanthridine can be further modified to react with alkenes or(bromoethynyl)benzene under suitable conditions for the synthesis of core framework of conjugated organic polymer materials.In chapter three, we introduced palladium-catalyzed aminoamidation and aminocyanation of alkenes to form 2-substituted indolines, tetrahydroisoquinolins and pyrrolidines, in which isocyanides were employed as the sources of amide and cyanide. Notably, the products could serve as the precursors of β-amino acids. The reaction has a broad substrate scope, and the products can be transformed into free amides via further debutylation.