Direct Amination of Nitro(pentafluorosulfanyl)benzenes through Vicarious Nucleophilic Substitution of Hydrogen

Abstract

Abstract1‐Nitro‐4‐(pentafluorosulfanyl)benzene underwent direct amination with 1,1,1‐trimethylhydrazinium iodide in the presence of tBuOK in DMSO to give 2‐nitro‐5‐(pentafluorosulfanyl)aniline in good yield. 1‐Nitro‐3‐(pentafluorosulfanyl)benzene, under similar conditions, gave 2‐nitro‐4‐(pentafluorosulfanyl)aniline, also in good yield. Reduction of either product with hydrogen in the presence of Raney nickel provided 4‐(pentafluorosulfanyl)benzene‐1,2‐diamine, which served as a precursor for the efficient synthesis of SF5‐containing benzimidazoles, quinoxalines, and benzotriazoles.

Amination of isopropanol to isopropylamine over a highly basic and active Ni/LaAlSiO catalyst

“…The reduction process referred to the reduction of groups such as nitrile, nitro and nitroso to amines. This method is usually convenient and economic, but it may be affected by the simultaneous presence of other groups that are easier to but do not need to be reduced [6,7]. The ammonolysis process can be applied for the conversion of many raw materials such as carboxylic acids, a-olefins, alkyl halides, aldehydes, ketones and alcohols to amines [8][9][10][11], among which alcohols are abundant and the ammonolysis process of alcohols with ammonia to amines appears environmentally benign, safe and selective [12].…”

Oxidative nucleophilic substitution of hydrogen in nitro(pentafluorosulfanyl)benzenes with alkyl Grignard and lithium reagents

“…The regioselectivity of the nucleophilic addition (5:6 ratio) ranged from 1:1 for i-PrMgBr to 2:1 for MeLi, which is much lower than in previously described VNS reactions with more stabilized (less reactive) carbon or oxygen nucleophiles to 2 [6,7]. VNS amination of 2 with Me 3 N + NH 2 I À proceeds exclusively Table 1 Optimization of n-propylmagnesium bromide (3a) addition to 1-nitro-4-(pentafluorosulfanyl)benzene (1) in position ortho relative to the nitro group [8]. This selectivity was attributed to steric reasons, where the SF 5 is a little more sterically demanding than the nitro group.…”

“…Additionally, a patent literature described a two-step conversion of diaryl disulfides to SF 5 -aromatics [3]. While S E Ar of 1 or 2 is very limited (nitration of 2 to give 3,5-dinitro(pentafluorosulfanyl)benzene in 33% yield was reported) [4], we have recently described S N Ar of the nitro group in compounds 1 and 2 with alkoxides and thiolates [5] and vicarious nucleophilic substitution (VNS) of the hydrogen with carbon [6], oxygen [7] and nitrogen [8] nucleophiles. Reduction of the nitro group in 1 or 2 to (pentafluorosulfanyl)anilines followed by acylation, S E Ar halogenation or diazotation (with follow-up reactions) provided number of SF 5 -benzene derivatives [2b,9].…”

Synthesis and nucleophilic aromatic substitution of 3-fluoro-5-nitro-1-(pentafluorosulfanyl)benzene

“…Under kinetic conditions the aromatic system is initially attacked by a nucleophile in ortho or para position to the nitro group, which was exploited in oxidative nucleophilic substitution for hydrogen reactions (ONSH) with organolithium or magnesium species or in vicarious nucleophilic substitution reactions (VNS) with carbon, oxygen or nitrogen nucleophiles [ 29 ]. VNS is a very powerful process for selective alkylation, amination and hydroxylation of nitroaromatics and was reported to proceed efficiently on 1 and its para -isomer [ 19 – 21 ]. In general, the reactions are characterized by short reaction times, low temperatures and an equimolar amount of the nucleophile.…”