Amine nitrogen, substitution

The polymers can be oxidized by differential pulse polarography. Their oxidation is metal-centered and leads to Ru(III) compounds. The potential is located aroimd -1-1.26 V (SCE). It can be stated that the polymers which contain the triphenylamine structure imits in the main chain show, as expected, an additional peak caused by the amine nitrogen. Substitution at the triphenylamine by electron-donating substituents lowers these potentials to 1.05 V (25), whereas acceptor substituents cause an increase of the oxidation potential (23). 

N or N ) with methyl groups results in nearly inactive agents. Similarly, aliphatic amine nitrogen substitution results in decreasing activity (NH2 > NHMe > NMe2 > N" Me3 [quaternary ammonium salt]) at both Hi and H2 receptors (2). 

A compound in which the —OH group of an acid is replaced by —NH2 is called an amide. When the —OH is replaced by —NHR, the product is called a nitrogen-substituted amide or, abbreviated, an N-substituted amide. One way to make amides is to react ammonia (or an amine) with an ester ... 

Reaction of A,A-dimcthylsullamoyl aziridines 323 and 325 with primary amines furnishes substituted 1,2,5-thiadiazolidine 1,1-dioxides 324 and 326, respectively, in a regioselective manner <06SL833>. Aziridine 325 is made from ( I /t,6,S ,Z)-bicyclo[4.2. l]non-3-en-9-one in two steps /V,/V-dimethylsulfamoyl imine formation using dimethylsulfamide and subsequent reaction with trimethylsulfoxonium ylide. The product from the reaction with 4-methoxy-benzyl amine can be subsequently manipulated (debenzylation and derivatization) to give the alternative nitrogen substitution pattern in a controlled manner. 

The drawback of this reaction is its extremely high sensitivity to the steric bulk of the nitrogen substitutent. When the analogous /V-benzylimine 101 was subjected to the standard hydrosilylation conditions, the reaction gave 55% conversion and 47% ee with prolonged reaction time (96 hours). A practical way to overcome this problem is to employ a nucleophilic promoter to convert the intermediate into a more reactive species. In this case, it has been found that primary amines have the most pronounced effect on the reaction. For example,... 

Conformational effects on 15N shifts in substituted cyclohexanes make an axial NH2 more shielded than an equatorial one. Also, 15N resonances are deshielded by ft substitution more extensively than are 13C resonances of cyclic hydrocarbons, but the magnitude of the effect depends on the degree of nitrogen substitution. Carbons in the y position shield the nitrogen in a manner analogous to 13C, but to a smaller extent in methanol than in cyclohexane solutions, and less for tertiary amines than for primary and secondary amines. These differences have been attributed in part to possible conformational influences on the stereoelectronic relationships between the lone pair and the C—C bonds. 

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. ... 

Carbonyl ylides derived from nitrogen-substituted carbonyl moieties provided for the synthesis of very stable push-pull dipolar intermediates. Although these compounds are quite stable, they still have sufficient reactivity to engage in cycloaddition and related processes. Carbonyl ylides derived from amides have been trapped in intermolecular cycloadditions to give aminals (Scheme 4.34) (56). 

As noted by Patterson and Holm, a sharp decrease in potential was also observed by Dockal etal. when amine nitrogens were substituted for thioether sulfurs in the acyclic ligand series. 

Specialty Amines. Some substituted nitrogenous compounds can provide similar benefits. Esters of 2-aminocrotonate and bis-2-aminocrotonate, and appropriately substituted dihydropyridines, eg, 3,5-bis-lauryloxycarboxy-2,6-dimethyl-1,4-dihydropyridine [37044-66-7] and... 

Aniline may be made (I) hy Ihe reduction, with iron or tin in HOI, of nitrobenzene, and (2) by the amination of chlorobenzene by healing with ammonia to a high temperature corresponding to a pressure of over 200 atmospheres in the presence of a catalyst (a mixture of cuprous chloride and oxide). Aniline is the end-point of reduction of most mono-nitrogen substituted benzene nuclei, as nitrosobenzene, beta-phenylhydroxylamine. azoxybenzene, azobenzene, hydrazobenzene. Aniline is detected by the violet coloration produced by a small amount of sodium hypochlorite. 

Quinuclidine (1) is a saturated bicyclic system with a bridgehead nitrogen atom. It has, in contrast to tertiary aliphatic amines and -substituted piperidines, a rigid structure. The atoms forming the quinuclidine ring are incapable of changing their relative positions by rotation around bond axes. These bond axes are included in the bicyclic system with each ring in the boat form. 

The hydrogen atoms of ammonia can be replaced, one by one, by equivalent radicles—methyl, CH3 ethyl, C2H5 to form a series of compounds called the amines or substituted ammonias in which nitrogen is undoubtedly tervalent. The amines are distinguished as primary, secondary, or tertiary, according as one, two, or three of the hydrogen atoms in ammonia are replaced by these radicles. Thus ... 

Andronati and co-workers reported a detailed study of the A-basicity of compounds 203 (X = H, Me R1 = H R2 = H, Br, Cl, Me) which contain amide, imine, and amine nitrogens in one molecule. The basicities, obtained from the half-neutralization potentials in potentiometric titrations, showed 203 to be monoacidic bases the basicity varied predictably with substitution and fell between the stronger quinoxaline-2-ones and the weaker l,4-benzodiazepine-2-ones. Ultraviolet spectroscopic studies demonstrated that the amino, not the imino, nitrogen was N-protonated (83CHE337). 

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