Studies On New Synthetic Methods Based-on C(sp~2)-H And C(sp~3)-H Bond Functionalization

The functionalization C-H bond had already became an efficient synthetic strategy in modern synthetic organic chemistry in the construction of C-C and C-heteroatom bonds, these bond constructions were widely used in the synthesis of natural products, pharmaceutical active molecules and new materials etc. In our works included in this dissertation, by making use of the C-H functionalization as key transformation, a class of new synthetic methods involving the functionalization of C(sp~2)-H and C(sp~3)-H bonds were explored and established, respectively.First, we explored the synthetic method by employing the strategy of multicomponent reactions to the C-H activation reactions, and realized the one-pot installation of 8-aminoquinoline(AQ) directing group and palladium-catalyzed β-C(sp~2)-H arylation of benzamides. Starting from commercially available reagents 8-aminoquinoline, benzoyl chlorides and iodobenzenes, the 2,6-biarylated or 6-arylated benzamides were smoothly acquired. Ulike the conventional direct group assisted C-H activation, the prior operations for installing the directing group and related purification of substrates were skiped in our method, which siginicantly reduced the chemical consumption and enhanced the atom and step economy.Susequently, we expanded the method to the functionalization of inert C(sp~3)-H bond. With the catalysis of Pd(OAc)2, the multicomponent reactions involving the installation of AQ directing group and the β-C(sp~3)-H arylation of aliphatic amides. Both mono- and di-arylated products were efficiently synthesized by using 8-aminoquinoline, aliphatic aryl chlorides and iodobenzenes.Further more, the C-H activation reactions employing new directing group containg chelating oxygen atom(o-hydroxylaniline). With also the tactic of multicomponent, one-pot procedure, the palladium-catalyzed domino reactions installing hydroxylaniline directing group and arylating the benzamide β-C(sp~2)-H bonds were achieved. The application of the new directing group expanded the scope of C-H activation-based synthesis, and concept of multicomponent reactions method improved the synthetic sustainability.Finally, the synthesis of indoly thioesters via the indole C3-H sulfenylation was studied. By directing using thiophenols as sulfenylating reagents, a variety of C3-sulfenylated indoles were efficiently synthesized with high yield with NaOH promoter. The simple and mild conditions of the method allowed for easy scale up synthesis.