Hydroxylamine-O-sulfonic Acid

Direct and Practical Synthesis of Primary Anilines through Iron-Catalyzed C–H Bond Amination

“…Halogen substituents, which can be reactive under transition-metal catalysis, were also tolerated under our reaction conditions, demonstrating that our protocol efficiently complements traditional amination reactions proceeding through halogen cross-coupling. Resonance donors, such as halogens, methoxy group, and acetamide, directed the amination to the para position (7,8,9). Inductive donors, as in 6 and 10, did not have a strong directing effect.…”

“…However, while serving as a proof-of-concept, these early protocols were greatly limited in scope and yields, most likely because of the instability of HSA in solution. 9 Considerable research efforts have recently targeted the development of more efficient and broadly applicable catalytic intermolecular C−H amination reactions for the preparation of functional molecules. Directed approaches to C−H amination are very useful when suitably placed functional groups can serve to facilitate the C−H bond functionalization step.…”

“…Notably, Kovacic and Minisci reported the direct amination of simple benzene derivatives using hydroxylamine O -sulfonic acid (HSA) and an aluminum or iron catalyst, respectively. However, while serving as a proof-of-concept, these early protocols were greatly limited in scope and yields, most likely because of the instability of HSA in solution . Considerable research efforts have recently targeted the development of more efficient and broadly applicable catalytic intermolecular C–H amination reactions for the preparation of functional molecules.…”

Metal-free synthesis of secondary amides using N-Boc-O-tosylhydroxylamine as nitrogen source via Beckmann rearrangement

“…They have found wide application in C–H amination, aziridination, amidation, hydroamination, amination, etc. 8 These reagents bring in several advantages over other traditionally used reagents, such as mild reaction conditions, good functional group tolerance, and easy purification, among others. However, their preparation has some inherent limitations, that is, an additional step is needed for N -Boc deprotection in a strong acidic medium such as TFA, they can be explosive and highly unstable after deprotection ( e.g.…”

Direct and Stereospecific Synthesis of N‐H and N‐Alkyl Aziridines from Unactivated Olefins Using Hydroxylamine‐O‐Sulfonic Acids

“…[8] However, no aziridination products were detected. After a thorough literature survey of inexpensive yet powerful aminating agents, we noted that hydroxylamine- O -sulfonic acid (HOSA) [9] has the potential to be the optimal reagent for our purposes: (a) HOSA has been widely used for the synthesis of amines, as well as for the preparation of nitriles, oximes, amides and various nitrogen-containing heterocycles; [10] (b) HOSA does not contain a nitro group and it has robust thermal stability (decomposition temperature: 208–211 °C) and is a widely available and cost-effective commercial source of electrophilic nitrogen; (c) the byproduct derived from HOSA is an inorganic sulfate after workup, which can be conveniently removed by simple aqueous extraction. Among publications focused on HOSA, several reports on olefin hydroamination drew our attention.…”