Photo-induced catalytic C−H heteroarylation of group 8 metallocenes

Abstract

Summary: Possessing a characteristic sandwich-type structure, metallocenes have been widely used by the chemistry community. However, the direct catalytic C−H heteroarylation of metallocenes still remains underexplored. Here, we report an efficient catalytic protocol for C−H heteroarylation of group 8 metallocenes (M = Fe, Ru) under light irradiation. This intermolecular cross coupling features directing group free, mild conditions and a wide substrate scope. Preliminary mechanistic studies suggest that the newly formed C−C bond is constructed through electrophilic radical substitution of the metallocene with a heteroaryl radical, which is generated via an oxidative quenching pathway.

Keywords

• ferrocene
• ruthenocene
• C-H heteroarylation
• photoredox
• radical reaction