Enzyme catalysis can be an attractive alternative for the synthesis of 1H-and 2Hindazoles, especially to provide a synthetic route with a lower environmental impact. At the same time, it can facilitate the expansion of the indazole synthesis toolbox and enable enzymatic cascades, e.g. for further diversification of indazoles by enzymatic Nmethylation . To date, however, the enzymatic synthesis of indazoles remains an unmet challenge, despite the presence of indazoles in natural products . Nitroreductases (NRs) are known to catalyze the reduction of nitro (-NO2) compounds to amines (-NH2) via nitroso (-NO) and hydroxylamine (-NHOH) intermediates . However, the reaction catalyzed by NRs usually leads to incomplete reduction to the final amine compounds and to the accumulation of nitroso and hydroxylamine intermediates . Recently, a photoenzymatic system was developed allowing the NR-catalyzed reaction of aromatic nitro compounds to be directed selectively to amines, azoxy or azo compounds, depending on the reaction conditions . Without the assistance of the photocatalytic system, the nitroso intermediate was found to be most dibicult to reduce by the NR BaNTR1 from Bacillus amyloliquefaciens, leading to a significant accumulation of this intermediate. Inspired by the possibility of generating reactive nitroso intermediates that can lead to spontaneous N-N bond formation , we hypothesize that an NR-based reaction could potentially lead to selective indazole formation. This requires the generation of reactive nitrosobenzylamine intermediates that spontaneously form the desired indazole scabold when the cyclization reaction occurs faster than the enzymatic reduction.