A comparison of ring-chain tautomerism in heterocycles derived from 2-aminobenzenesulfonamide and anthranilamide

A number of anthranilamide and 2-aminobenzenesulfonamide derivatives with aromatic aldehydes and 1,3-dicarbonyl compounds were synthesized. Substituted benzaldehyde derivatives of neither aminoamides showed tautomerism in solutions. Reaction products of 2-aminobenzenesulfonamide with p-substituted benzoylacetic aldehydes and p-substituted benzoylacetones undergo ring-chain tautomerism with a good linear correlation between the ring-chain equilibrium constants (log K, where K=[ring]/[chain]) and the Hammett-Brown σ⁺ parameters of the aromatic substituents. The equilibrium constant was measured for the reaction products of 2-aminobenzenesulfonamide with unsubstituted benzoylacetaldehyde at several temperatures which enabled the enthalpy and entropy of this reaction to be evaluated.     

Mono- and Diamination of 4,6-Dichloropyrimidine, 2,6-Dichloropyrazine and 1,3-Dichloroisoquinoline with Adamantane-Containing Amines

N-heteroaryl substituted adamantane-containing amines are of substantial interest for their perspective antiviral and psychotherapeutic activities. Chlorine atom at alpha-position of N-heterocycles has been substituted by the amino group using convenient nucleophilic substitution reactions with a series of adamantylalkylamines. The prototropic equilibrium in these compounds was studied using NMR spectroscopy. The introduction of the second amino substituent in 4-amino-6-chloropyrimidine, 2-amino-chloropyrazine, and 1-amino-3-chloroisoquinoline was achieved using Pd(0) catalysis.     

Homologous series of novel adamantane–colchicine conjugates: synthesis and cytotoxic effect on human cancer cells

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Arylation of adamantanamines: V. Palladium-catalyzed amination of isomeric chloroquinolines with diamines of the adamantane series

Palladium-catalyzed arylation of diamines of the adamantane series with isomeric 2-, 4-, and 6-chloroquinoline was studied, and optimal conditions for the synthesis of the corresponding N,N′-diaryl derivatives were found. N,N-Diarylation products of primary amino groups in the diamines bearing 2-aminoethyl and 4-aminophenyl substituents were readily formed.     

Palladium-catalyzed amination in the synthesis of aza- and diazacrown trismacrocyclic compounds

Palladium-catalyzed C-N-cross-coupling of N,N′-bis(bromobenzyl) diazacrown compounds with two equivalents of 1-aza-15-crown-5 and 1-aza-18-crown-6 ethers furnished trismacrocyclic compounds with isolated macrocycles. Macrotricyclic cryptands were obtained when diazacrown ethers were used as N-components.     

Synthesis of optically active 2,7-disubstituted naphthalene derivatives and evaluation of their enantioselective recognition ability

The palladium-catalyzed amination was used to synthesize 2,7-diamino derivatives of naphthalene containing two chiral substituents and fluorophore groups (dansyl, 7-methoxycoumarin, 6,7-dimethoxycoumarin, 6-aminoquinoline). The synthesized compounds were studied by UV absorption and fluorescence spectroscopy in the presence of individual enantiomers of amino alcohols and salts of 21 metals. The possibility of using these compounds as fluorescent detectors for optically active compounds and metals was examined. In the presence of (S)-leucinol, the diquinoline derivative showed enhanced emission with a maximum at shorter wavelengths, which is not typical of its (R) isomer. This fact can be used for the recognition of these enantiomers. A number of naphthalene derivatives can be considered as potential fluorescent chemosensors for Cu^II cations due to the total fluorescence quenching in the presence of this metal.

     

Arylation of adamantanamines: IV. Palladium-catalyzed arylation of amines of adamantane series with isomeric chloroquinolines

Palladium-catalyzed arylation of diverse amines of the adamantane series with isomeric chloroquinolines was investigated. The 2-chloroquinoline is the most reactive, however the best yields of the N-arylation products are most frequently obtained in the reaction with the less reactive 6-chloroquinoline. The applicability of the reaction is limited by the size of the substituent at the amino group. In some instances the noncatalytic amination of chloroquinolines was possible.     

The first solid phase synthesis of pincer palladium complexes

Both dimeric μ-chlorine bridged and monomeric bidentate Pd(II) complexes with SCN hybrid pincer-type ligands, bearing thiophosphoryl group and imine moiety of the benzothiazole ring as coordination arms, formed in the reaction with (PhCN)(2)PdCl(2) under kinetic control (20 °C, dichloromethane solution) were readily converted into the corresponding SCN pincer complexes via solid phase synthesis (neat, 200 °C, 15 min). The synthesis of pincer complexes can be performed also by heating (200 °C, 5 min) of a homogeneous mixture of the initial reactants, namely, the ligand and (PhCN)(2)PdCl(2), obtained by manual grinding in a mortar. The efficacy of solid phase approaches is comparable with the analogous synthesis in solutions under severe conditions.     

Arylation of Adamantanamines: X. Palladium- and Copper-Catalyzed Heteroarylation of Adamantane-Containing Amines with Bromopyridines

Russian Journal of Organic Chemistry - The catalytic efficiencies of palladium(0) and copper(I) complexes in the amination of 2-bromopyridine and its fluorine-containing derivatives with...