Self‐ or Acridinium‐Catalyzed Electrophotosynthesis of Thiocyanato Heterocycles from Activated Alkenes

While the emergence of electrophotochemistry provides opportunities, such a chemistry at this stage suffers from limited reaction types and high photocatalyst loadings. A self‐catalyzed electrophotosynthesis as well as one with a low photocatalyst loading is presented. These external‐oxidant‐free cyclizations are enabling and applicable to a range of activated alkenes, affording a diverse array of thiocyanato heterocycles including 4‐pyrrolin‐2‐ones, isoquinoline‐1,3‐diones, indolo[2,1‐a]isoquinolin‐6(5H)‐ones, benzoimidazo[2,1‐a]isoquinolin‐6(5H)‐ones and indolin‐2‐ones, and the protocols are amenable to the late‐stage diversification of complex molecular architectures as well as gram‐scale syntheses. Sunlight could serve as the light source, and the reaction could be conducted in an all‐solar‐driven mode using a commercially available photovoltaic panel to produce electricity.