Transition Metal-Catalyzed C-H Functionalization And C-B Bond Oxidation

Transition metals catalysis is one of the most important strategies in current organic chemistry. In particular, transition metal-catalyzed C-H functionalization provides an elegant method for the rapid construction of complex molecules. This dissertation is mainly focused on the studies of ruthenium catalyzed cascade reaction involving C-H functionalizations.1. We have developed a single ruthenium-catalyzed cross-metathesis/intramolecular-hydroarylation cascade, which offeres a practical and efficient synthesis of structurally diverse and complex tetrahydrocarbazoles in good to excellent yields (up to98%) via a sp2C-H functionalization at C-3position of indole. It was documented that the substituents on the N-1position of polycyclic indoles had great effects on their biological activities. As a result, N-phenyl indolyl alkene was applied to this strategy, which could provide various N-phenyl substituted tetrahydrocarbazoles in good yields (81-88%).2. An asymmetric functionalization of sp3C-H bonds adjacent to a nitrogen atom in tetrahydroisoquinolines, by the combination of the photocatalytic aerobic oxidation and the metal-catalyzed alkynylation reaction, have been described. Biologically important chiral tetrahydroisoquinoline alkaloids could be obtained by the use of this novel dual catalysis procedure.3. An efficient approach to carbonyl compounds has been disclosed through an aerobic oxidative cleavage of C-B bond using visible-light photoredox. This procedure has a wide broad substrates scopes and high functional group tolerance. More importantly, some organic dyes can be employed as photocatalysts in the oxidative cleavage reaction under irradiation by visible light, affording the corresponding carbonyl compounds in high yields (up to86%).