Excited State Anions in Organic Transformations. Photoangeregte Anionen in organischen Reaktionen

Utilizing light is a smart way to fuel chemical transformations as it allows to selectively focus the energy on certain molecules. Many reactions involving electronically excited species proceed via open‐shell intermediates enabling novel and unique routes to expand the hitherto used synthetic toolbox in organic chemistry. The direct conversion of non‐prefunctionalized, less activated compounds is a highly desirable goal to pave the way towards a more sustainable and atom‐economic chemistry. Photoexcited closed‐shell anions have been shown to reach extreme potentials in single electron transfer reactions and reveal unusual excited state reactivity. It is therefore surprising, that their use as reagent or as photocatalyst is limited to a few examples. In this review, we briefly discuss the characteristics of anionic photochemistry, highlight pioneering work and show recent progress which has been made by utilizing photoexcited anionic species in organic synthesis.