Studies On The Synthesis Of Heterocycles By Rhodium(?)-Catalyzed C-H Activation Based On N-Methoxyamides As Directing Group

C-H bonds are ubiquitous in organic molecules. The activation of C-H bond is a very efficient and direct strategy to increase the molecular diversity. Transition metal catalyzed C-H bond activation has the advantages of step-economy, atom-economy and can be realized under mild conditions. Rh-Catalyzed C-H activation has been developed rapidly in recent years, which has shown the unique catalytic activity compared with other metal catalytic systems. This thesis has synthesized various important heterocyclies by Rh(III)-catalyzed C-H bond activation with N-methoxyamides as directing groups.The thesis is divided into five chapters. The first chapter mainly reviews the Rh-catalyzed C-H bond fiinctionalization. The thesis proposal is presented in chapter two.Chapter three describes a novel aryl C-H bond hydroamination using N-Boc-hydroxya mine via synergistic combination of rhodium and copper catalysis for the convenient synthesis of benzo[c]isoxazol-3(1H)-ones. In this process, the unstable and transient nitrosocarbonyl compounds were generated in situ by aerobic oxidation and used as coupling partner to form both C-N and C-0 bonds. The reactions proceed smoothly at room temperature in the open air, which features mild reaction conditions and easy operation.Chapter four describes kinetic control of Rh(III)-catalyzed annulation of C-H bonds with quinones for the chemoselective synthesis of dibenzo[b,d|pyran-6-ones, benzo[d]nap htho[1,2-6]pyran-6-ones, hydrophenanthridinones and phenanthridinones. In these reactions, distinct types of complex molecules are constructed from identical starting materials at different temperatue using the same catalyst system by tuning the role of the directing groups, which acts selectively as an electrophile in the synthesis of dibenzo[b,d]pyran-6-ones and benzo[d]naphtho[1,2-b]pyran-6-ones, whereas as a nucleophile in the synthesis of hydrophenanthridinones and phenanthridinones.In chapter five, we report a novel [4+5]-cyclization of N-methoxyamides with quinone monoketal through Rh(?)-activated C-H bonds activation. Interestingly, bicyclic 2-aza-[4.3.1]decane products are obtained via a C-C bond coupling and intramolecular aza-Michael addition process, which is very different from the pathways of the previous reported couplings of N-methoxyamides with quinones and 4-hydroxycyclohexa-2,5-dien ones.