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[Display omitted] • Various Lewis acids catalyse the electrophilic amidation of arenes in acetic acid. • O-acetyl acetohydroxamic is used as atom-efficient amidating agent. • Kinetic and spectroscopic data point towards electrophilic aromatic substitution. Electrophilic arene C H amination constitutes an intrinsically more atom- and step-economical pathway towards arylamines than C X → C N methods. However, most literature examples are restricted to arenes with extensive directing groups (DG) and/or nitrogen coupling partners with large leaving groups (LG). Moreover, only few cases of EAs using cheap metals (e.g. , Fe) have been reported. Herein, we demonstrate the catalytic activity of various Lewis acids in the electrophilic amidation of simple arenes with O -acetyl acetohydroxamic acid in acetic acid. With 5 mol% FeIII(citrate)·H 2 O, up to 27 % yield was achieved, whereas 5 mol% BiCl 3 gave up to 31 % yield. Instability of the amidation agent and product inhibition were identified as the yield-limiting factors. The observed regioselectivity, as well as kinetic and spectroscopic data suggest an electrophilic aromatic substitution mechanism, in which acetic acid and the Lewis acid generate a highly electrophilic species from AcNHOAc. [ABSTRACT FROM AUTHOR]

N−O σ bonds containing compounds are versatile substrates for organic synthesis under transition metal catalysis. Their ability to react through both polar (oxidative addition, formation of metallanitrene, nucleophilic substitution) and radical pathways (single electron transfer, homolytic bond scission) have triggered the development of various synthetic methodologies, particularly toward synthesizing nitrogen‐containing compounds. In this review, we discuss the different modes of activation of N−O bonds in the presence of transition metal catalysts, emphasizing the experimental and computational mechanistic proofs in the literature to help to design new synthetic pathways toward the synthesis of C−N bonds. [ABSTRACT FROM AUTHOR]

We reported a new electrophilic amination of various primary, secondary and tertiary alkyl, benzylic, allylic zinc and magnesium organometallics with O‐2,4,6‐trimethylbenzoyl hydroxylamines (O‐TBHAs) in 52–99 % yield. These O‐TBHAs displayed an excellent long‐term stability and were readily prepared from various highly functionalized secondary amines via a convenient 3 step procedure. The amination reactions showed remarkable chemoselectivity proceeding without any transition‐metal catalyst and were usually complete after 1–3 h reaction time at 25 °C. Furthermore, this electrophilic amination also provided access to enantioenriched tertiary amines (up to 88 % ee) by using optically enriched secondary alkylmagnesium reagents of the type s‐AlkylMgCH2SiMe3. [ABSTRACT FROM AUTHOR]

Hypervalent iodine reagents have the ability of inverting the polarity of functional groups bound to iodine, a reactivity known as umpolung. This reactivity makes hypervalent iodine compounds highly attractive for the creation of electrophilic synthons of known nucleophiles, resulting in novel synthetic disconnections and the formation of new Nu(nucleophile)−N bond. Electrophilic sources of nitrogen‐based groups have been known for many decades and are of great synthetic importance. Traditionally, these reagents are limited to few examples. With the use of hypervalent iodine, the transfer of a wide diversity of nitrogen sources became a possibility. This review compiles the latest reported examples of hypervalent iodine reagents capable of electrophilic transfer of nitrogen‐based groups. It showcases the preparation of such reagents, their synthetic utility, and reaction mechanisms involving these group transfer reagents. [ABSTRACT FROM AUTHOR]

Owing to the prevalence of nitrogen-containing compounds in natural products and important pharmaceutical agents, chemists, have actively searched for the development of efficient and selective methodologies allowing for the facile construction of carbon–nitrogen bonds. Over the last decade, transition metal-catalyzed C–N bond construction via electrophilic amination reaction has emerged as an attractive approach for the synthesis of various organic molecules and pharmaceuticals. Particularly, O-benzoylhydroxylamines as an electrophilic aminating agent have proven to be the best and most widely used in both academic and industrial research. In this review, we highlight the key contributions to the recent transition metal-catalyzed C–N bond formation reactions using O-benzoylhydroxylamines as an aminating agent and their relevant mechanistic insights. [ABSTRACT FROM AUTHOR]

We started our study by preparation two ketoximes. Later, there were studies to reveal these ketoximes' effects in the electrophilic amination reaction with organocadmium reagents. Primarily, it was observed that arylcadmium iodides could not be reacted with ketoximes at room temperature in the absence of a catalyst. CuCN was a suitable catalyst for this electrophilic amination reaction of arylcadmium iodides and allowed the preparation of functionalized aniline derivatives in good yields under mild reaction conditions. We obtained the results indicated that the yield of primary arylamines was strongly dependent on the steric and electronic effects of organocadmium reagent and amination agent. In the case of both amination reagents, meta-substituted arylamines were obtained in higher yields than para-substituted arylamines. We observed that acetone O-(4-chlorophenylsulfonyl)oxime, 1, as an aminating agent, was more successful than acetone O-(2-Naphthylsulfonyl)oxime, 2, in the synthesis of functionalized arylamines by electrophilic amination of corresponding aryl cadmium iodides. In this method, there is no cadmium release to the environment. [ABSTRACT FROM AUTHOR]

In this study, a CuCN catalyzed process of the diarylcadmium compounds by electrophilic amination method was developed using novel acetone O-(4-chlorophenylsulfonyl)oxime and acetone O-(2-naphthylsulfonyl)oxime. Herein, it has been demonstrated that primary arylamines can easily be obtained with good yields at room temperature by CuCN catalyzed amination of diarylcadmium reagents. It was settled down that the yield of primary arylamines depended strongly on the steric and electronic effects of organocadmium reagent and amination agent. In both amination reagents, meta-substituted arylamines were obtained in higher yields than para-substituted aryl amines. All reactions involving organocadmiums were carried out under an argon atmosphere by standard syringe/cannula methods. Amines as reaction products were separated from the reaction mixture as benzamide derivatives and purified and melting points, 1H NMR analysis determined their accuracy. [ABSTRACT FROM AUTHOR]

Electrophilic amination reaction was performed with lower order and higher order organocuprates using acetone O-(4-Chlorophenylsulfonyl)oxime (1). It was proceeded smoothly at room temperature in the presence of organocuprates to provide the corresponding primary amines in good yields with 10 and 60 min, respectively. The primary amine yields of the electrophilic amination of bromomagnesium organocyanocuprates and dibromomagnesium diorganocyanocuprates were obtained 52–72% and 58–83%, respectively. We observed that higher order organocuprates were more successful than lower order organocuprates in the synthesis of functionalized arylamines by electrophilic amination. [ABSTRACT FROM AUTHOR]

Isoxazolo[3,4-b]pyridin-3(1H)-ones are 'spring-loaded' compounds that quantitatively react with iminium salts derived from formaldehyde and secondary amines to yield fluorescent Safirinium dyes. The mechanism and energetics of the above tandem Mannich–electrophilic amination reaction have been investigated experimentally and using theoretical methods. The hybrid B3LYP functional with GD3 empirical dispersion and range-separated hybrid functional ωB97XD, both combined with a PCM model, were applied to acquire the energetic profiles of the studied reaction with respect to the structure of secondary amine and isoxazolone used. Diastereoselectivity of the tandem reactions involving iminium salt derived from L-proline has been rationalized theoretically by means of density functional theory calculations. [ABSTRACT FROM AUTHOR]

A practical method for the synthesis of N‐(2‐carbonylaryl) benzenesulfonamides via an iron‐catalyzed electrophilic amination of sodium sulfinates with anthranils is described. This redox‐neutral transformation has high atom efficiency and is achieved under simple and mild reaction conditions. A wide range of anthranils and sodium sulfinates were compatible in this transformation. Moreover, the synthetic potential of this methodology was further demonstrated by the synthesis of various useful N‐heterocycles and derivatives. [ABSTRACT FROM AUTHOR]

The preparation of a new class of aliphatic amino iodane(III) reagents has been realized with the N‐TMS−amine and acetoxybenziodazole participated in the formation of N−I bond. The amino‐containing iodane(III) reagent 2 d was characterized by single‐crystal X‐ray diffraction, which revealed the expected hypervalent iodane distorted T‐shaped geometry. A practical copper‐catalyzed, directed electrophilic amination of aryl amines employing amino‐iodane(III) as amination agents was disclosed that proceeded smoothly without external additives. [ABSTRACT FROM AUTHOR]

Cobalt(III)-catalyzed electrophilic amination of inert C(sp3)–H bonds of weakly coordinating thioamides with readily accessible anthranil derivatives was accomplished under mild conditions, with good functional group tolerance, thus providing various amino aldehydes and amino ketones. Moreover, our protocol with the versatile [Cp*Co(MeCN)3 ][SbF6 ]2 features excellent atom-economy and oxidant-free conditions, and allows facile late-stage functionalization. [ABSTRACT FROM AUTHOR]

Electrophilic amination of methyl N-(hydroxyphenyl)carbamates and methyl N-(4-methoxyphenyl)carbamate with sodium azide in 86% polyphosphoric acid (PPA) at 55–60°C regioselectively afforded methyl N-(3-amino-2-hydroxyphenyl)-, N-(4-amino-3-hydroxyphenyl)-, N-(3-amino-4-hydroxyphenyl)-, and N-(3-amino-4-methoxyphenyl)carbamates, i.e., the amino group entered the ortho position with respect to the hydroxy or methoxy group. The reactions of methyl N-(4-methoxyphenyl)carbamate with nitromethane and nitroethane in 80% PPA at 95–110°C gave methyl N-(3-carbamoyl-4-methoxyphenyl)carbamate and methyl N-(3-acetamido-4-methoxyphenyl)carbamate, respectively. Methyl N-[4-(N′-hydroxyethanimidamido)phenyl]carbamate was obtained by reaction of 4-[(methoxycarbonyl)amino]benzoic acid with excess nitroethane in 86% PPA at 125°C. [ABSTRACT FROM AUTHOR]

A wide range of alkyl‐, aryl‐ and heteroarylzinc halides were aminated with highly functionalized alkyl, aryl, and heterocyclic azides. The reaction proceeds smoothly at 50 °C within 1 h in the presence of FeCl3 (0.5 equiv) to furnish the corresponding secondary amines in good yields. This method was extended to peptidic azides and provided the arylated substrates with full retention of configuration. To demonstrate the utility of this reaction, we prepared two amine derivatives of pharmaceutical relevance using this iron‐mediated electrophilic amination as the key step. [ABSTRACT FROM AUTHOR]

Isoxazolo[3,4-b]pyridin-3(1H)-ones are ‘spring-loaded’ compounds that quantitatively react with iminium salts derived from formaldehyde and secondary amines to yield fluorescent Safirinium dyes. The mechanism and energetics of the above tandem Mannich–electrophilic amination reaction have been investigated experimentally and using theoretical methods. The hybrid B3LYP functional with GD3 empirical dispersion and range-separated hybrid functional ωB97XD, both combined with a PCM model, were applied to acquire the energetic profiles of the studied reaction with respect to the structure of secondary amine and isoxazolone used. Diastereoselectivity of the tandem reactions involving iminium salt derived from L-proline has been rationalized theoretically by means of density functional theory calculations.

One‐pot synthesis of 2‐aminobenzoxazoles through copper‐catalyzed electrophilic amination of benzoxazoles with O‐benzoyl hydroxylamines is described. The direct magnesation of benzoxazoles with the readily available iPrMgCl generated benzoxazolylmagnesium reagents in situ and these reagents were treated with electrophilic amines in the presence of 10 mol‐% Cu(OAc)2 and ZnCl2 under mild reaction conditions. A variety of 2‐aminobenzoxazoles were obtained in good to excellent yields. [ABSTRACT FROM AUTHOR]

Keywords: electrophilic amination; hypervalent iodine reagent; umpolung; transfer of N-containing groups EN electrophilic amination hypervalent iodine reagent umpolung transfer of N-containing groups 1 1 1 07/05/23 20230703 NES 230703 B The Cover Feature b illustrates the potential and versatility of hypervalent iodine(III) compounds as the root of several methodologies that enable the introduction of nitrogen-based functional groups. Electrophilic amination, hypervalent iodine reagent, umpolung, transfer of N-containing groups Cover Feature: Reactivity of Hypervalent Iodine(III) Reagents Bearing Transferable N-Based Groups (Eur. J. Org. [Extracted from the article]

This paper reports a novel approach for the direct and facile synthesis of 1,2-oxyamino moieties via an intermolecular copper-catalyzed oxyamination of olefins. This strategy utilizes O-benzoylhydroxylamines as an electrophilic amine source and carboxylic acids as a nucleophilic oxygen source to achieve a modular difunctionalization of olefins. The reaction proceeded in a regioselective manner with moderate to good yields, exhibiting a broad scope of carboxylic acid, amine, and olefin substrates.

Abstract: A copper‐catalyzed net hydroamination of vinylphosphine boranes with hydrosilanes and O‐benzoylhydroxylamines has been developed. The reaction proceeds regioselectively to form the corresponding α‐aminophosphine boranes of potent interest in medicinal and pharmaceutical chemistry. This copper catalysis is based on an umpolung, electrophilic amination strategy and provides a new electrophilic amination approach to α‐aminophosphine derivatives. Additionally, although still preliminary, asymmetric synthesis has also been achieved by judicious choice of a chiral bisphosphine‐ligated copper complex. [ABSTRACT FROM AUTHOR]

Abstract: A CuCl/(R,R)‐PTBP‐BDPP‐catalyzed regioselective and enantioselective aminoboration of simple and unactivated terminal alkenes with bis(pinacolato)diboron (pinB‐Bpin) and hydroxylamines has been developed. The amino group and boryl group were incorporated at the internal position and terminal position, respectively, and the corresponding chiral β‐borylalkylamines were obtained with good to high enantiomeric ratios. The asymmetric copper catalysis allows rapid and concise transformation of readily available olefinic feedstock‐like materials into functionalized chiral alkylamines of high potential in medicinal and pharmaceutical chemistry. [ABSTRACT FROM AUTHOR]

Abstract: The first general protocol for the direct reductive N‐functionalization of aliphatic nitro compounds is presented. The nitro group is partially reduced to a nitrenoid, with a mild and readily available combination of B2pin2 and zinc organyls. Thereby, the formation of an unstable nitroso intermediate is avoided, which has so far severely limited reductive transformations of aliphatic nitro compounds. The reaction is concluded by an electrophilic amination of zinc organyls. [ABSTRACT FROM AUTHOR]

Abstract: Aryl‐ and heteroarylzinc pivalates can be aminated with O‐benzoylhydroxylamines at 25 °C within 2–4 h in the presence of 2.5–5.0 % CoCl2⋅2 LiCl to furnish the corresponding tertiary arylated or heteroarylated amines in good yields. This electrophilic amination also provides access to diarylamines and aryl(heteroaryl)amines. A new tuberculosis drug candidate (Q203) was prepared in six steps and 56 % overall yield by using this cobalt‐catalyzed amination as the key step. [ABSTRACT FROM AUTHOR]

Crocagin A ( 1) combines an attractive molecular structure with an unusual biosynthesis and bioactivity. An efficient synthesis of crocagin A is presented that hinges on an early formation of the heterotricyclic core, an electrophilic amination, and the stereoselective hydrogenation of a tetrasubstituted double bond. This synthesis confirms the absolute configuration of crocagin A and provides access to the natural product and derivatives thereof for further biological testing. [ABSTRACT FROM AUTHOR]

An exceptionally general electrophilic amination, which directly transforms commercially available nitroarenes into alkylated aromatic aminoboranes with zinc organyl compounds was developed. The reaction starts with a two-step partial reduction of the nitro group to a nitrenoid, which is used in situ as the electrophilic amination reagent. To facilitate isolation, the resulting air- and moisture-sensitive aminoboranes were reacted with a range of electrophiles. The method not only represents a direct transformation of nitro compounds into electrophilic amination reagents but also provides an elegant alternative to dehydrocoupling methods for the generation of aminoboranes. [ABSTRACT FROM AUTHOR]

The synthesis and the evaluation as organocatalysts of new chiral guanidines derived from benzimidazoles in the enantioselective α-amination of 1,3-dicarbonyl compounds using di-t-butylazodicarboxylate as aminating agent is herein disclosed. The catalysts are readily synthesized through the reaction of 2-chlorobezimidazole and a chiral amine in moderate-to-good yields. Among all of them, those derived from (R)-1-phenylethan-1-amine (1) and (S)-1-(2-naphthyl)ethan-1-amine (3) turned out to be the most efficient for such asymmetric transformation, rendering good-to-high yields and moderate-to-good enantioselectivities for the amination products. [ABSTRACT FROM AUTHOR]

Transition-metal-catalyzed electrophilic amination has been developed into a powerful tool for C−N bond construction. So far, O-benzoylhydroxylamines are the most widely used electrophilic aminating reagents. Herein, we summarize the recent advances of O-benzoylhydroxylamines involved in electrophilic amination catalyzed by transition metals. Several pioneering studies and some of the relevant mechanisms are discussed in this review. [ABSTRACT FROM AUTHOR]

A copper-catalyzed regioselective and stereospecific aminoboration of vinylsilanes with bis(pinacolato)diboron (pinB-Bpin) and hydroxylamines has been developed. In the presence of a CuCl/MeO-dppbz catalyst, the boryl group and amino group are incorporated at the β position and α position, respectively, and the corresponding β-boryl-α-aminosilanes are obtained with good diastereoselectivity. The boryl group is a good latent functional group, and subsequent manipulations provide a variety of β-functionalized α-aminosilanes of great potential in medicinal chemistry. Additionally, preliminary application to asymmetric catalysis is also described. [ABSTRACT FROM AUTHOR]

The use of readily available chiral trans-cyclohexanediamine-benzimidazole derivatives as bifunctional organocatalysts in the asymmetric electrophilic amination of unprotected 3-substituted oxindoles is presented. Different organocatalysts were evaluated; the most successful one contained a dimethylamino moiety (5). With this catalyst under optimized conditions, different oxindoles containing a wide variety of substituents at the 3-position were aminated in good yields and with good to excellent enantioselectivities using di-tert-butylazodicarboxylate as the aminating agent. The procedure proved to be also efficient for the amination of 3-substituted benzofuranones, although with moderate results. A bifunctional role of the catalyst, acting as Brønsted base and hydrogen bond donor, is proposed according to the experimental results observed.