Aminating reagents

JV-Diisopropylaniline (Amination of an Arylcopper Reagent with a Lithium 

Diethyl Aminomalonate (Amination of a ft-Dicarbonyl Compound with 

JV-tert-Butylbenzylamine (Amination of an Alkyllithium Compound with a Lithium 

Ethyl (iV-Acetylamino)phenylacetate (Amination of an Ester Enolate with an 

Ethyl tert-Butoxycarbonylamino(cyano)phenylacetate (Amination of a Cyanoacetic 

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

Hydro-de-diazoniation seems to be an unnecessary reaction from the synthetic standpoint, as arenediazonium salts are obtained from the respective amines, reagents that are normally synthesized from the hydrocarbon. Some aromatic compounds, however, cannot be synthesized by straightforward electrophilic aromatic substitution examples of these are the 1,3,5-trichloro- and -tribromobenzenes (see below). These simple benzene derivatives are synthesized from aniline via halogenation, diazotization and hydro-de-diazoniation. Furthermore hydro-de-diazoniation is useful for the introduction of a hydrogen isotope in specific positions. 

Scheme 26 Synthesis of optically active amines 91 using the chiral amination reagent 89...

Dissolve the biotin-PEG -amine reagent in reaction buffer at a concentration of 25 mM. 

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. 

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 . ... 

Amines are generally prepared by nucleophilic amination, which is a coupling of carbon electrophiles with a nucleophilic amination reagent, NR2, and Ni and Pd catalyzed reaction of aryl halides with arylamines (Hartwig-Buchwald amination) . Thus, the direct C—N bond formation between carbon nucleophiles and electrophilic nitrogen functionality R2N+ constitutes an example of the umpolung methodology. 

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. 

TABLE 1. O-Organylhydroxylanrine-type electrophUic amination reagents... 

For the synthesis of secondary amines, Beak, Basha and Kokko used iV-alkyl-0-methylhydroxylamines li and Ij. The method of treating 1 equivalent of amination reagent with 1 equivalent of methyllithium, followed by reaction with 1 equivalent of organo-lithium to be aminated, was found more effective than reacting 1 equivalent of amination reagent with 2 equivalents of the organoUthium (Scheme 8). ... 

The use of 2,4-dinitrophenylhydroxylamine (DPH) Ih as an amination reagent for a-metallated methyl 9-fluorenecarboxylate and diethyl a-phenyhnalonate (equation 6a and b) was reported by Sheradsky and coworkers . ... 

The authors screened a number of Af-monosubstituted 0-benzoylhydroxylamines 2g-i and A, A -disubstituted 0-benzoylhydroxylamines 2a-f as amination reagents for diorgan-ozincs, and these reagents were found to couple with simple and functionalized diorganoz-incs in the presence of Cu salts to provide secondary amines (Scheme 17) and tertiary amines (Scheme 18), respectively. ... 

Hydroxylamine O-sulfonic acid 3p has found wide application in the nonsymmetric and asymmetric amination of organoboron compounds and its use as an amination reagent has been well reviewed . 

Boche and coworkers also reported that coupling of 1-alkynyl carbanions with N,N-dialkylamino groups could be achieved in preparing higher-order lithium 1-alkynylcuprates and they used 3h as the amination reagent (Scheme 25). ... 

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. ... 

The same group expanded their study to see how well nitrenes derived from N-(alkoxycarbonyl) 0-(arenesulfonyl)hydroxyfamines 3i-o perform in a-amination of a,fi-unsaturated carljonyl compounds by aziridination. Good results are obtained when a,-unsaturated carboxylates and y-lactones are reacted with the amination reagents 3k, 31 and 3n in the presence of CaO. 

Similar investigations were reported by this group using /S-oxoesters as the precursors to be aminated products in the presence of CaO and 3n as amination reagent . Ethyl acetoacetate gave a-monoaminated and a-bisaminated products (Scheme 35) depending on the substrate base ratio. An A-aminated product was also obtained in the amination of ethyl a-methylacetoacetate. 

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