Directed Decarbonylation Of Unstrained Aryl Ketones Via Nickel Catalyzed C-C Bond Cleavage

Indoles have a ubiquitous structural units widely existing in natural products which exhibit active drug molecules such as antibacterial and anticancer.Due to the presence of having"dominant structure",scientists have been exploring relentlessly.Transition-metal-catalyzed C-C bond activation provides a completely simple and efficient mean to synthesize or modify active molecules.The cleavage of C-C bond is the fundamental issue in organic chemistry,and one ofthe most efficient approaches for decarbonylation of ketone derivatives to C-C bond activation is the use of transition metal as catalysts.The transition metal can effectively insert the C-C bond,release CO,and form a new C-C bond.Given the ubiquity of carbonyl compounds,the decarbonylative C-C activation followed by a C-C forming process provides a unique synthesis strategy using carbonyl groups as a“traceless handle”,and has an important synthetic value because they alow the preparation of compounds that lack a carbonyl moiety from a more readily available ketone precursor.Research on transition-metal-catalyzed decarbonylation has always been the focus of my research team.In the thesis,we propose a nickel-catalyzed decarbonylation of unstrained diaryl ketones.The reaction catalyzed by a combination of Ni?cod?₂ and an electron-rich N-heterocyclic carbene ligand was achieved for the first time using a strong coordination group orientation strategy.A wide range of functional group tolerance,regional selectivity and high yields?up to 98%?are observed.In order to further probe the mechanism of this transformation,we investigated the minitma or saddle points in detail by DFT calculations and reasonably proposed the reaction mechanism.In summary,we have developed an alternative method for the construction of biaryl using inexpensive nickel catalysts,enriching the use of indoles in drug synthesis.