Aryl diamine

Grubbs reported the synthesis of several N, N -aryl substituted imidazolinium salts 35 from chiral Ar,AT -aryl diamines obtained by palladium-catalyzed amination of the appropriate aryl bromide with (li, 2i )-diaminocyclohexane... 

Influence of Molecular Structure and Substituents on Antiozonant Properties of Aryl Diamine Compounds... 

The influence of molecular structures and substituents on the antiozonant properties of a series of related aromatic diamine compounds was studied. The relative effectiveness of the compounds was determined by viscometric techniques and by comparison of the rate of degradation of protected vuicanizates. Results indicate that unsymmetrical p-phenylenediamine derivatives are less effective than analogous symmetrical compounds as antiozonants. The protective capacity of the antiozonants decreases as the size or number of the N-hydrogen substituents, or the distance between the amine groups, increases. The comparative stability of the free radicals of aryl diamines, in terms of the theory of resonance, is utilized to explain the relative inhibiting properties of the chemicals examined. 

DELMAN, RUFF, SIMMS, AND ALLISON-ARYL DIAMINE COMPOUNDS... 

This paper presents the results of an investigation of some of the above materials and other structurally related aryl diamine chemicals. Data are also presented on the comparative inhibiting properties of three representative protectant chemicals used as additives in typical SBR vulcanizates. 

Influence of Molecular Structure. The changes in per cent of initial viscosity index with ozonization time for SBR solutions protected by symmetrical and un-symmetrical aryl diamine compounds are shown in Figures 1 and 2. Figure 3 compares... 

Figure 3. Comparison of symmetrical and unsymmetrical aryl diamines...

It can be concluded from the data presented in the figures that the relative effectiveness of the related aryl diamine chemicals studied corresponds with the comparative stability of their free radicals, in accordance with the theory of resonance. 

The authors express their appreciation to T. A. Werkenthin, head of Elastomers Branch, Bureau of Ships, Washington, D. C., for his interest and sponsorship of this work, and to I. J. Stanley and J. Mironov for their efforts in establishing the chemical structure of several of the aryl diamine derivations used in the investigation. 

Our data now provide a reasonable explanation why there may be no obvious defect in iron metabolism in Wilson s disease. Despite the reduction in Cp, suflScient ferroxidase activity remains to prevent anemia. Remember that less than one-tenth of the normal level of ferroxidase is sufficient to cause a maximum mobilization of iron in both in vivo and in vitro experimental systems (46, 50), Thus, in Wilson s disease the level of serum ferroxidase may never become sufficiently low to be rate-hmiting in iron utilization. It was also mentioned earlier that the ferroxidase activity in Wilson s disease serum was higher than expected from the aryl-diamine oxidase activity. Richard W. Topham in our laboratory has been able to isolate a ferroxidase quite distinct from Cp which appears to remain relatively intact in Wilson s disease serum (27). Another possible explanation was oflFered by Hansen et cd, (52) who proposed citrate as an alternative ferroxidase in low Cp serum. 

From l-hydroxy-2-naphthaldehyde and alkyl or aryl diamines ... 

Aryl diamines gave poorer results. Treatment of p-phenylenediamine hydrochloride with diphosgene in dioxane gave only poor yields (23% or less) of the diisocyanate, even though the reaction was carried out under almost the same conditions as used with phosgene. When the free base was used instead of the hydrochloride, the yield of the diisocyanate was improved to 47%. 

In 2012, Martin-Matute and co-workers [83] reported another pincer ruthe-nium(II) complex-catalyzed selective A -alkylation of (hetero)arylamines with primary alcohols. When the method was extended to aliphatic amines, the authors found that the aliphatic amine moiety could not be oxidized or alkylated. Inspired by this finding, aminoalcohols were later used as the alkyl source for iV-alkylation of (hetero)aromatic amines. iV-Arylated diamines were selectively obtained in excellent yield (Eq. 10). 

A simple one-pot strategy for the synthesis of differently substituted quinoxalines from 1,2-aryl diamines and 2-bromomalonic ester at room temperature (Scheme 65) xmder solvent- and catalyst-free conditions has been investigated by Haidar et al. [95]. The mechanism followed is nucleophilic substitution, amide formation, followed by in situ oxidative aromatization. The compoxmd 54a, a key synthetic intermediate for the synthesis of a 5-HT3 receptor antagonist, could be effectively synthesized by this reaction protocol. 

SCHEME 65 Quinoxaline synthesis from 1,2-aryl diamines and 2-bromomalonic ester at room temperature. 

A direct synthesis of substituted pyridines in yields of about 50% is found in the treatment of acetylene and an alkyl nitrile in the presence of a cobalt catalyst. A general method for the synthesis of 3- and 3,4-substituted furans from ketones has been developed. A new route to various heterocycles with 2 or more heteroatoms has been presented, as well as a procedure involving 1,3- or 3,3-cyclization on difunctional nucleophiles, such as hydrazine, hydroxylamine, alkyl and aryl-diamines. 76 77... 

BCOs exhibit variable substrate specificity plant and fungal laccases, for example, typieally exhibit wide substrate specificity and can oxidize a variety of aminophenols, diphenols, and aryl diamines. The mechanism for these enzymes is consistent with Mareus theory [37], and suggests that oxidation occurs in the outer sphere and there is likely no specific binding pocket Conversely, some BCOs such as ascorbate oxidase (specifieity toward L-ascorbate) [38,39] and ceruloplasmin (specificity toward Fe +) [40,41] are often stereospecilic and highly substrate specific [42]. 

Laccase Magnetic mesoporous silica nanoparticles [MMSNPs Immobilized enzyme Kn, = 3.28 mM, Kcat = 155.4 mln" free enzyme Kn, = 1.26 mM, Kcat = 138.9 min" Oxidation of phenols, polyamines, lignin, and aryl diamines application in Bio-sensors, biofuels and waste water treatment [51]... 

Figure 6 Indicates attempts to build elastomeric properties Into a polymer by Incorporating a fluoroether chain Into a polylmlde system (. Line 1 shows an aryl diamine polymer Intermediate prepared In a lengthy series of synthesis steps from a perfluoroalkylene ether dlcarboxyllc acid. The polymer Is prepared from the reaction of the diamine with perfluoro-hexamethylene-bis(phthalic anhydride). As expected, the polymer had excellent thermal stability, but, again. Its low-temperature properties were deficient. For example, en X + y = 0, the Tg was 130 C when x + y = 1, the Tg was 110 C and when x + y = 3, the Tg was 80 C. With this system, we are unable to achieve requisite (lialn flexibility because of a preponderance of rigid aromatic groups that Inhibit elasticity and cause a raising of the T beyond practical limits for our Intended purpose as a sealant material. The fluoroether segment Is simply too short to yield a useful low-temperature elastomer.

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