Metal-Free Functionalization of N,N-Dialkylanilines via Temporary Oxidation to N,N-Dialkylaniline N-Oxides and Group Transfer

Abstract

A simple set of protocols for the controlled elaboration of anilines is reported allowing access to a diverse array of aminophenols, aminoarylsulfonates, alkylated anilines, and aminoanilines in 29–95% yield in a single laboratory operation from easily isolable, bench-stable N,N-dialkylaniline N-oxides. The introduction of new C–O, C–C, and C–N bonds on the aromatic ring is made possible by a temporary increase in oxidation level and excision of a weak N–O bond.

Palladium-Catalyzed Synthesis of N,N-Dimethylanilines via Buchwald–Hartwig Amination of (Hetero)aryl Triflates

“…For example, para-tert- butyl dimethylaniline ( 3d ) was readily oxidized with m -CPBA to produce the corresponding N -oxide ( 5 ) in 83% yield (Scheme ). This N -oxidized compound can be converted into the ortho-substituted phenol in 91% yield . Also, dimethylaniline ( 3a ) smoothly underwent an alkynyl–methyl bond formation in the presence of the CuBr catalyst under oxidative conditions in 57% yield …”

“…HRMS (ESI-TOF, m / z ): calcd for C 11 H 17 N [M + H] + 164.1439, found 164.1440. The analytical data is in accordance with that reported in the literature …”

“…The possibility of the global derivatization around the core structure turns N , N -dimethylaniline into a versatile building block in organic synthesis (Scheme ). The activating nature of the N , N -dimethylamine group allows for the diverse decoration of the arene. − Furthermore, the unique redox activity of alkylamines can be exploited for C­(sp 3 )–C and C­(sp 3 )–heteroatom bond formations. , This reaction palette was recently extended by reports on the utilization of N , N -dimethylanilines as electrophiles in cross-coupling reactions . Irrespective of these developments, the synthesis of this structural motif is less advanced.…”

Synthesis of Quinoline-Based NNN-Pincer Nickel(II) Complexes: A Robust and Improved Catalyst System for C–H Bond Alkylation of Azoles with Alkyl Halides

“…Liquid reagents were flushed with argon prior to use. The compounds 2-bromo- N , N -dimethylaniline, 2-bromo- N , N -diethylaniline, ( Me2 NNN Q )­H, (THF) 2 NiBr 2 , substituted benzothiazoles, and 5-arylazoles were synthesized according to previously described procedures. All other chemicals were obtained from commercial sources and were used without further purification.…”

Transformation of N , N -dimethylaniline- N -oxides into N -methylindolines by a tandem Polonovski–Mannich reaction

“…1 The aniline N-oxides undergo an O-acylation event with a host of electrophiles, after which an O ? C group transfer excises the weak N-O bond to give an iminium ion, and loss of a proton restores aromaticity and electron density at nitrogen (Scheme 1, Eq.…”