Solvent-controlled chemoselective N-dealkylation-N-nitrosation or C-nitration of N-alkyl anilines with tert-butyl nitrite

Abstract

A metal-free, acid-free and chemoselective N-dealkylation-N-nitrosation or C-nitration of N-alkyl anilines has been developed.

Pathways for N-Nitroso Compound Formation: Secondary Amines and Beyond

“…Guo et al reported the N -dealkylation/ N -nitrosation of tertiary aromatic amines using TBN in organic media . It was found that the nature of the solvent has a pivotal role in the chemoselectivity of the process because both N -nitrosation and C -nitration are plausible pathways in air.…”

“…For the C -nitration, the NO 2 radical and substrate react through an electrophilic radical addition process (Scheme , path a). For N -dealkylation- N -nitrosation, the t BuO radical directly abstracts a hydrogen atom from the N-Me group providing an α-amino radical, which is immediately oxidized into an iminium intermediate that leads to formaldehyde and the corresponding secondary amine which can be nitrosated by TBN (Scheme , path b) …”

“…Guo et al reported the N-dealkylation/N-nitrosation of tertiary aromatic amines using TBN in organic media. 71 C-nitration are plausible pathways in air. In most tested organic solvents, a mixture of N-nitroso and C-nitro compounds were formed, though reaction chemoselectivity can be partially controlled through choice of solvent.…”

“…For N-dealkylation-Nnitrosation, the t BuO radical directly abstracts a hydrogen atom from the N-Me group providing an α-amino radical, which is immediately oxidized into an iminium intermediate that leads to formaldehyde and the corresponding secondary amine which can be nitrosated by TBN (Scheme 28, path b). 71 Jia et al reported a similar approach to effect selective and efficient N-dealkylation/N-nitrosation of tertiary anilines with TBN in the presence of catalytic TEMPO in acetonitrile (MeCN) at room temperature (Scheme 29). 72 To obtain mechanistic insight into the N-nitrosation process with secondary amines, a detailed kinetic study was carried out by Iglesias and coworkers.…”

Divergent g-C3N4-catalyzed Reactions of Quinoxalin-2(1H)-ones with N-Aryl Glycines under Visible Light: Solvent-Controlled Hydroaminomethylation and Annulation

“…Divergent synthesis is of great significance in organic synthetic chemistry , owing to the rapid acquisition of structurally diverse chemical scaffolds from the same starting materials, − which has also been considered as a highly attractive synthetic strategy for the synthesis of heterocyclic compounds. , Generally, different products could be generated from the identical starting materials through the variation of functional groups, − catalysts, solvents, − additives, − and ligands to switch the reaction pathways. This strategy provides an indispensable route to build a molecular library with maximum scaffold diversity. − Therefore, the divergent synthesis of various scaffolds from easily available starting materials is urgently pursued and expected.…”