Nitration of Derivatives of Imidazo[1,5‐a]pyridine via C−H Functionalization with Fe(NO₃)₃ ⋅ 9H₂O as a Promoter and a Nitro Source

An additive‐free, mild, and regioselective C(1)−H nitration of imidazo[1,5‐a]pyridine derivatives was developed. This protocol features the use of easily handled, commercially available, and nontoxic Fe(NO 3 ) 3 ⋅ 9H 2 O both as a nitration source and as a promoter, exhibits good functional group compatibility, and generates the desired nitrated products in acceptable to excellent yields. Mechanistic studies proposed that the nitration reaction may involve a radical C−H functionalization process.