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Aminations electrophilic

S.08.4.2.1 Synthesis of diaziridines by electrophilic amination of carbonyl-amine adducts... [Pg.230]

Diaziridines (151) are formed from a carbonyl compound, an amine and an electrophilic aminating reagent (B-67MI50800, 79AHC(24)63>. [Pg.230]

The reaction of 2-chloro-4,5-dihydroimidazole 347 with hydroxylamine-O-sulfonic acid gives 2-hydroxylamino-4,5-dihydroimidazolium-O-sulfonate 348, which reacts with aldehydes and cyclic ketones to give the imidazo[l,2-f] fused 4,5-dihydro-l,2,4-oxadiazoles 350 (Scheme 58). Mechanistically, the reaction may be explained by the reaction of an imidazoline NH with the carbonyl followed by intramolecular electrophilic amination of the anionic oxygen present in the resultant intermediate 349 and elimination of the sulfate group <2003JOC4791>. [Pg.296]

Since then, optically active a-aminophosphonates have been obtained by a variety of methods including resolution, asymmetric phosphite additions to imine double bonds and sugar-based nitrones, condensation of optically active ureas with phosphites and aldehydes, catalytic asymmetric hydrogenation, and 1,3-dipolar cycloadditions. These approaches have been discussed in a comprehensive review by Dhawan and Redmore.9 More recent protocols involve electrophilic amination of homochiral dioxane acetals,10 alkylation of homochiral imines derived from pinanone11 and ketopinic acid,12 and alkylation of homochiral, bicyclic phosphonamides.13... [Pg.14]

Lithium t-butyl A-tosyloxycarbamate, Bu C CNTos Li+, is an electrophilic aminating agent for organometallic compounds RM (MeLi, BuLi, j-BuLi and PhCu) to give,... [Pg.551]

The efficiencies of 0-(diphenylphosphinoyl)hydroxylamine and hydroxylamine-O-sulphonic acid as electrophilic aminating agents have been compared96. The conversion of... [Pg.551]

The action of chloroamine and bromoamine on organometallic reagents has been reviewed102 and a comprehensive review of electrophilic aminations of carbanions has appeared103. Alkyl, alkenyl and aryllithium compounds are converted into tertiary amines 84 by reaction with the mesityl compounds 83 (R2 = Me or Et Ar = 2,4, 6-MesCeHj)104. [Pg.552]

Electrophilic amination reactions by means of oxaziridines have been reviewed105. Cyclohexylidenehydrazines 86 are formed from secondary amines such as diethylamine, dibutylamine and morpholine and the spirooxaziridine 85105. [Pg.553]

Direct formation of 5,5-dihydro-5-iminothianthrene by reaction with hydroxylamine mesitylsulfonate presumably involves, first, electrophilic amination at sulfur (74TL1973). Electrophilic S-bromination (see also Section III, A, 3, b) must be presumed to initiate the conversion of thianth-rene into the sulfurane 25 by reaction with bromine in the presence of the alcohol (RfOH = l,l,l,3,3,3-hexafluoro-2-phenyl-2-propanol) (77JOC3222). [Pg.330]

Fig. 2.13 Examples of hydroboration/amination using Rh-QUINAP complexes and electrophilic aminating agents. (I) Catecholborane, 1 mol% (S)-QUINAP-Rh catalyst, THE, RT, 1 h 2 equiv. MeMgCI in THE, 30 min solid H2NOSO3H,... Fig. 2.13 Examples of hydroboration/amination using Rh-QUINAP complexes and electrophilic aminating agents. (I) Catecholborane, 1 mol% (S)-QUINAP-Rh catalyst, THE, RT, 1 h 2 equiv. MeMgCI in THE, 30 min solid H2NOSO3H,...
Cannizzaro reaction, 2, 3 Carbanion, electrophilic amination, 72, 1 Carbenes, 13, 2 26, 2 28, 1 Carbene complexes in phenol and quinone synthesis, 70, 2... [Pg.586]

Electrophilic amination is an important reaction in which an electrophilic nitrogen atom (R2N+) carried out by an amination reagent (R R N—L) is transferred to all kinds of nucleophiles (Nu ) (equation 1). The leaving group L is displaced by the nucleophile in the amination reaction. [Pg.304]

This methodology is also an important and potentially valuable method for C—N bond formation using the amination of carbon nucleophiles with electrophilic nitrogen transfer reagents (Scheme 1) Amination of ordinary carbanions and a-carbanion derived from carbonyl compounds and nitriles provides an important method for the synthesis of amines and a-amino carbonyl compounds and nitriles", respectively. For this purpose, a number of electrophilic amination reagents, which are synthetic equivalents of the R2N+ synthon, have been developed and the synthetic potential of electrophilic amination of carbon nucleophiles has been studied in detail . ... [Pg.304]

Due to the synthetic and biological importance of amines and a-aminoketones, acids and esters, the introduction of amino functionality into carbon nucleophiles provides a convenient and practical route for their synthesis "In addition, a number of electrophilic amination methodologies have been developed for the asymmetric synthesis of amines and a-aminocarbonyl compounds " ". [Pg.304]

Substituted hydroxylamines 1-5 (R = R = H) and their A-mono- or A,A-disub-stituted derivatives 1-5 have been used extensively for electrophilic amination of both carbanions and enolates since the first report in 1938 on the use of 0-methylhydroxylamine 1 (R = Me) for conversion of Grignard reagents to primary amines. Oximes 7 (Z = H) have found limited applicability as amination reagents for carbon nucleophiles and then-use was first reported in 1907. Ketone 0-sulfonyloximes 7 (Z = SO2R) have recently been developed. [Pg.304]

This chapter on electrophilic amination using O-substituted hydroxylamines 1-5 and oximes 7 is focused on the various methods that have been reported for the amination of carbon nucleophiles. Synthetic aspects and applications of the methods for C—N bond formation are accompanied by a brief discussion of the reaction mechanisms. The preparation of O-substituted hydroxylamines and oximes has not been considered in detail. This review covers the literature up to August 2007 and is partly based on reviews on the electrophilic amination of carbanions and a-amination of carbonyl compounds. ... [Pg.305]

The only reported example of the use of O-phenylhydroxylamine Ig for electrophilic amination of carbanions is the conversion of phenyhnagnesium bromide into aniline. ... [Pg.308]

TABLE 2. 0-Acylhydroxylamine-type electrophilic amination reagents... [Pg.312]

Recently, a direct kinetic study on the amination of substituted phenyhnagnesium bromides using Af,Af-dimethyl O-mesitylenesulfonyl hydroxylamine 3b as amination reagent has been reported by Erdik and Ate Ulkii . Rate data, the Hammett relationship and activation entropy support an Sn2 displacement of the carbon nucleophile on the electrophilic nitrogen. These results are consistent with the competition kinetics for electrophilic amination of substituted phenyl Grignard reagents with O-methylhydroxylamine In. ... [Pg.319]

There are a few reports on the use of oximes as electrophilic amination reagents. Since 1984, ketone O-sulfonyloxknes have found applicability as amino transfer reagents to car-banions. In the reaction of organometaUic compounds with oximes, carbanions attack the carbonyl carbon of the oxime, giving Af-substituted hydroxylamines as addition products (Scheme 53, path a). However, a number of scattered reports have been also published on the formation of aziridines by a-deprotonation, followed by addition (path b) or formation of azirines by a-deprotonation before addition (path c). Addition of carbanions to azirines also yields aziridines, which are hydrolyzed to a-aminoalcohols. [Pg.332]

In this chapter, C—N couplings, e.g. substitution reactions of carbanions on nitrogen atom of oximes to yield primary amines, have been reviewed. A list of oximes and 0-sulfonyloximes used for electrophilic amination is given in Table 6. These reagents aminate carbanions to A-organylimines as isolable intermediates which are hydrolyzed to primary amines (Scheme 53, path d Scheme 54). Depending on the organometaUic... [Pg.332]

The first example of the amination of Grignard reagents with oximes is the reaction of benzaldoxime 6a with a-naphthylmagnesium bromide (equation 24, path a) to yield a-naphthylamine (Scheme 53, path d, electrophilic amination product). In contrast, the reaction of benzaldoxime with phenyhnagnesium bromide (equation 24, path b) was reported to give Af-benzhydrylaniline (Scheme 53, path e product). [Pg.333]

The discussion in this chapter highlights the performance of O-substituted hydroxylamines and oximes as electrophilic amino transfer reagents. In conclusion, the scope of electrophilic amination will be greatly enhanced by developing new O-substituted hydroxylamines and oximes and further improvements in electrophilic amination would be of great synthetic interest. [Pg.338]

In addition to alkylation with alkyl halides, electrophilic amination has been achieved with di-(/< /r-butyl) azodi-carboxylate <2004HCA1016>, and reactions with aldehydes have generated alcohol derivatives <1999JOC8668, 2003TL671>. Dialkylation at the 5-position has also been achieved <1998TA3881>. [Pg.180]


See other pages where Aminations electrophilic is mentioned: [Pg.229]    [Pg.575]    [Pg.283]    [Pg.1005]    [Pg.92]    [Pg.247]    [Pg.627]    [Pg.533]    [Pg.550]    [Pg.552]    [Pg.304]    [Pg.318]    [Pg.338]    [Pg.1065]    [Pg.1332]   


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Aldehydes electrophilic amination

Amination electrophilic

Amination electrophilic aromatic substitutions

Amination electrophilic, review

Amination reactions aryl electrophiles

Amine reaction with electrophilic olefins

Amines electrophilic aromatic

Amines electrophilic aromatic substitution

Amines electrophilic reactions

Asymmetric electrophilic amination

Carbanion, electrophilic amination

Carbon-nitrogen bond formation electrophilic amination

Carbonyl compounds electrophilic amination

Chiral Electrophilic Aminating Reagents

ELECTROPHILIC AMINATION OF CARBANIONS

Electrophilic Amination of Ketone Enolates

Electrophilic Amination of Organozinc Halides

Electrophilic Amination of Silyl Ketene Acetals

Electrophilic amination Friedel-Crafts alkylation

Electrophilic amination and reactions with nitroarenes

Electrophilic aromatic amination

Electrophilic reactions amination

Electrophilic reactions amination, aryl electrophiles

Hydroxylamine, 0- electrophilic / /-aminations

Known electrophilic aminating agents

Stereoselective Electrophilic Amination with Sulfonyloxycarbamates and Azodicarboxylates

Stereoselectivity electrophilic amination

Substitution, electrophilic amination

Versus electrophilic amination

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