Three photon absorbing photocatalyst enabled defluorinative amination of fluoroarenes
We have developed a photocatalytic system that explores the latent potential of a new photocatalyst HATCN. The architecture of this flat molecule is well poised to pose it as a great photooxidant, that can also afford multiple redox states. The excited reduction potential of HATCN is calculated as 2.83 V which corroborates well with its strong oxidizing behavior. A large number of SNAr reactions have been conducted over a wide variety of fluororenes with varying electronic nature. The catalytic efficiency of the photocatalyst has been demonstrated by successful reaction to both electron-neutral and -poor fluoroarenes. Furthermore, the great utility of this developed protocol has been established by applying this method over a large number of building blocks of drugs and pharmaceutically important moieties. An extensive studies delineate the involvement of three photons for one catalytic cycle, that is unprecedented in photocatalysis. Furthermore, the redox modularity of the photocatalyst gives access to the oxidant and reductant behavior of the same molecule at different stages of the catalytic cycle. This discovery of novel mechanistic paradigm will translate in solving challenging photochemical processes.