It is a well-known phenomenon in drug discovery that many bioactive compounds share the same scabold . Among these "privileged groups", bicyclic N-heterocycles such as benzimidazoles, benzoxazoles, and (tetrahydro)isoquinolines are overrepresented, making them very important targets for synthetic strategies. Consequently, many of these privileged groups have already been accessed via biocatalytic routes, which are often discussed in the context of sustainable synthesis . However, enzymatic routes have not been described for all N-heterocyclic groups, such as in the case of indazoles. These molecules are found in many commercially successful drugs, such as granisetron, axitinib, niraparib and pazopanib, which are used to treat nausea and cancer (Figure ). The 1H-and 2H-tautomers of indazoles are equally important for drug development. In the case of indazoles without N-substitutions, the 1H-tautomer dominates because it is more stable . and 2H-indazoles (blue) . The detailed reactions are shown in the supporting Scheme S1; C) Developed nitroreductase-triggered formation of 1H-and 2H-indazoles.