Prof. Dr. Golo Storch, Mainz: Flavin Catalysis: From Biomimetic
Transformations to New Reactivity

Flavoenzymes are responsible for a multitude of different transformations in nature, many of which are well-understood mechanistically. Learning from these activities and adapting them for syntheti-cally valuable reactions in the organic laboratory is one of our main aims. While some reactions work with the isolated (–)-riboflavin cofactor, others require carefully designed synthetic variants, which we explore and apply. Following our strategy, we have developed catalytic methods inter alia for reduction, oxidation, hydrogen atom transfer (HAT), and oxygenation.
In their excited state, flavins are strong single-electron oxidants, and they also serve as sensitizers after intersystem crossing (ISC). We recently discovered that the sensitization activity is significantly enhanced though an unusual ring-contraction, which proceeds with flavin 1 under basic conditions.