Intermolecular C-C/C-N σ-bond metathesis enabled by visible light.

Transition-metal-catalyzed double/triple bond metathesis reactions have been well-established due to the ability of transition-metal catalysts to readily interact with π bonds, facilitating the progression of the entire reaction. However, activating σ-bonds to induce σ-bond metathesis is more challenging due to the absence of π bonds and the high bond energy of σ bonds. In this study, we present a novel photo-induced approach that does not rely on transition metals or photosensitizers to drive C-C and C-N σ-bond metathesis reactions.

Two-in-One Role of Benzophenone in Photoinduced C(sp)-H Monofluoralkenylation: Hydrogen-Atom Transfer and Single-Electron Transfer.

A new protocol for monofluoralkenylation of C(sp)-H bonds with -difluoroalkenes was reported. In this protocol, benzophenone serves as a photocatalyst with dual roles of hydrogen-atom transfer and single-electron transfer. The excited state of benzophenone abstracts a hydrogen atom from a C(sp)-H bond to generate a corresponding carbon radical, which subsequently undergoes a radical addition/SET/β-F elimination process rather than radical-radical cross-coupling of previous work.