Arylamines s. Amines

In general, EC reactions are typically observed according to the following general rank order (by relative ease of oxidation) o,p-quinol and o,p-aminophenol > tertiary amine > m-quinol rv phenol rv arylamine > secondary amine thiol > thioether primary amines, aliphatic alcohols. (HDVs) each redox active metabolite are obtained from the response across adjacent EC-Array sensors. These data are a reflection of the kinetic and thermodynamic components of electron transfer reactions. Since chemical structure is a critical determinant of an analyte s redox behavior, the intrinsic generation of an HDV with EC-Array provides qualitative information for each species. 

Research into the mechanism of diazotization was based on Bamberger s supposition (1894 b) that the reaction corresponds to the formation of A-nitroso-A-alkyl-arylamines. The TV-nitrosation of secondary amines finishes at the nitrosoamine stage (because protolysis is not possible), but primary nitrosoamines are quickly transformed into diazo compounds in a moderately to strongly acidic medium. The process probably takes place by a prototropic rearrangement to the diazohydroxide, which is then attacked by a hydroxonium ion to yield the diazonium salt (Scheme 3-1 see also Sec. 3.4). 

The scope of allylic electrophiles that react with amines was shown to encompass electron-neutral and electron-rich ciimamyl methyl carbonates, as well as furan-2-yl and alkyl-substituted allylic methyl carbonates. An ort/io-substituted cinnamyl carbonate was found to react with lower enantioselectivity, a trend that has been observed in later studies of reactions with other nucleophiles. The electron-poor p-nitrocinnamyl carbonate also reacted, but with reduced enantioselectivity. Allylic amination of dienyl carbonates also occur in some cases with high selectivity for formation of the product with the amino group at the y-position over the s-position of the pentadienyl unit [66]. Arylamines did not react with allylic carbonates under these conditions. However, they have been shown to react in the presence of the metalacyclic iridium-phosphoramidite catalysts that are discussed in Sect. 4. 

Dimerization of arylamine cation-radicals is a prominent example of the product s steric hindrance effects on the reaction course. Although stable in AN, the A,A-dimethyl-p-toluidine dimerizes if its uncharged counterpart is present in the solution (Goto et al. 2002, Oyama and Goto 2003). The cation-radical loses a proton, and the parent amine reacts as a base, accepting this proton. Coupling of benzylic radicals is an understandable result of the following reaction ... 

Aliphatic S-alkylamidinoisothioureas (XIV R = R = Aik) and aryl-amines react readily (745) under conditions favouring the condensation of alkylcyanoguanidines with arylamines. This provides further evidence, though not proof, that the reaction involves intermediate alkylcyanoguanidines (X). 

This enzyme [EC 2.S.2.3], also known as arylamine sulfo-transferase, catalyzes the reaction of 3 -phosphoadeny-lylsulfate with an arylamine to produce adenosine 3, 5 -bisphosphate and an arylsulfamate. Primary and secondary amines which can act as substrates include aniline, 2-naphthylamine, cyclohexylamine, and octylamine. 

There has been a review of the effects of high pressure on the substitution reactions of amines with haloaromatic compounds, including polyhalobenzenes.17 Nucleophilic substitutions by amines often proceed readily in dimethyl sulfoxide (DMSO). The pAa values, in DMSO, have been reported for some ammonium ions derived from amines widely used as nucleophiles in, S Ar reactions.18 Correlations have been established19 between the oxidation potentials and the basicities of some arylamine and diarylamine anions and the rate constants for their reactions with aryl halides in DMSO. 

The mercuration of 1,5-hexadiene in the presence of aromatic amines, amides or carbamates is a suitable method for the preparation of 2,5-disubstituted pyrrolidines. The stereochemical outcome of this cyclization is strongly determined by the reaction conditions, 1,3-asymmetric induction depends on whether kinetic or thermodynamic control takes place. When mercury(II) acetate was allowed to react at — 20 °C in tetrahydrofuran with 1,5-hexadiene in the presence of an excess of arylamine (kinetic control), tra s-.V-substituted 2,5-dimethylpyrro-lidines 7 were the major product after reductive cleavage of the C —Hg bond88,89. 

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