Since we were able to identify an intermediate in the reaction, analyzed the reaction between 2-chloro-4-nitropyridine 2a and lithiated 4-chloroaniline 1b•Li(THF)2 using DFT calculations. The lowest energy pathway (Scheme 4) shows an exergonic conversion (ΔG = -26.5 kcal•mol -1 ) to the dilithium salt ArN(OLi)2 (II). Nucleophilic attack of lithiated aniline 1b•Li(THF)2 to nitropyridine 2a (TS-I, ΔG ǂ = +10.0 kcal•mol -1 ) affords σ H adduct I in a slightly exergonic step. Subsequent irreversible deprotonation of intermediate I by LiHMDS (TS-II, ΔG ǂ = +11.9 kcal•mol -1 ) would provide the ArN(OLi)2 species II. A computational survey of the proposed mechanism for the oxidation of PhN(O -)2 analogs supports the exergonic but rate-determining oxidation 20 of dilithium salt II by molecular oxygen (ΔG ǂ II-TSIII = +18.4 kcal•mol -1 ) to give 5a and lithium peroxide. Conclusion: The ONSH amination of nitro(hetero)arene and anilines can be effected using LiHMDS in THF at room temperature without the need for transition metal oxidants, cryogenic temperatures, and liquid ammonia. Reactions are done within 10 minutes and can be done open to air. The products generated herein require no more prefunctionalization than the presence of a nitro group on a (hetero)arene, to contrast with other C-N bond forming reactions such as SNAr, Buchwald-Hartwig, or Chan-Lam couplings. Here, nitroaniline products can be obtained in one step from a C-H bond. Currently only anilines are viable nucleophiles in this reaction, and not all nitro(hetero)arenes are compatible; nitro(hetero)arenes with ortho-halides undergo SNAr faster than ONSH (Scheme S3). DFT calculations and in situ IR experiments suggest a dianion mechanism with oxygen acting as the terminal oxidant, and that oxidation is rate-limiting. We view ONSH as an underappreciated tactic in medicinal and process chemistry and hope that these reactions can lead to more concise syntheses.