Showing papers in "Russian Journal of Organic Chemistry in 2007"
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TL;DR: In this article, a review of published data on the reactivity of thiols, specifically C-, N-, P-, and S-sulfanylation reactions, halogenolysis of S-H bond, dealkylation, and oxidation, are reviewed.
Abstract: Published data on the reactivity of thiols, specifically C-, N-, P-, and S-sulfanylation reactions, halogenolysis of S-H bond, dealkylation, and oxidation, are reviewed.
45 citations
TL;DR: The reaction of nitriles with sodium azide in the presence of ZnCl2 under microwave activation (MWA) leads to the formation of 5-tetrazoles in high yields.
Abstract: Reaction of nitriles with sodium azide in the presence of ZnCl2 under microwave activation (MWA) leads to the formation of 5-tetrazoles in high yields; therewith the process is 2–3 times shorter than the inactivated reaction.
33 citations
TL;DR: In this article, 1,1-diamino-2,2-dinitroethylene with glyoxal and formaldehyde in water solutions at pH 7-8 gave rise to 2-(dinitromethylene)imidazolidine-4,5-diol and 1, 1diaminofurazan respectively.
Abstract: Condensation of 1,1-diamino-2,2-dinitroethylene with glyoxal and formaldehyde in water solutions at pH 7–8 gave rise to 2-(dinitromethylene)imidazolidine-4,5-diol and 1,1-diamino-N,N′-bis(hydroxymethyl)-2,2-dinitroethylene respectively. Condensation products of 2-(dinitromethylene)imidazolidine-4,5-diol with acetonitrile, benzonitrile, urethane, 3,4-diaminofurazan were isolated. The reaction of 4,5-diacetamido-2-(dinitromethylene) imidazolidine sulfate with water in acetonitrile led to the formation of 2-(dinitromethylene)-5-methyl-1,2,3,3a,4,6a-hexahydroimidazo[4,5-d]imidazole. The dehydration of 2-(dinitromethylene)imidazolidine-4,5-diol in a system H2SO4-AcOH provided 2-(dinitromethylene)-2,3-dihydro-1H-imidazol-4-ol. 1,1-Diamino-N,N′-bis(hydroxymethyl)-2,2-dinitroethylene in sulfuric acid was converted into 4-(dinitromethylene)-1,3,5-oxadiazinane.
32 citations
TL;DR: In this article, a simple and effective synthesis of 3,4-dihydropyrimidin-2(1H)-one and 3.4-Dihydrocyclic aldehydes, methyl acetoacetate, and urea or thiourea in the presence of 10% of an acidic task-specific ionic liquid ([C4mim][HSO4]) as catalyst under microwave irradiation in the absence of a solvent was proposed.
Abstract: A simple and effective synthesis of 3,4-dihydropyrimidin-2(1H)-one and 3,4-dihydropyrimidine-2(1H)-thione derivatives has been developed on the basis of three-component condensation of substituted aromatic and heterocyclic aldehydes, methyl acetoacetate, and urea or thiourea in the presence of 10% of an acidic task-specific ionic liquid ([C4mim][HSO4]) as catalyst under microwave irradiation in the absence of a solvent. The proposed procedure ensures short reaction times (4.4–8 min) and good yields after purification by recrystallization.
31 citations
TL;DR: In this paper, a series of new hetarylazo indole dyes were synthesized by azo coupling of 2-phenyl-, 2-methyl-, and 1-methyl-1phenyl-1H-indole with diazonium salts.
Abstract: A series of new hetarylazo indole dyes were synthesized by azo coupling of 2-phenyl-, 2-methyl-, and 1-methyl-1-phenyl-1H-indole with diazonium salts derived from 5-methylsulfanyl-1H-1,2,4-triazol-3-amine, 1H-1,2,4-triazol-3-amine, 5-methylisoxazol-3-amine, and 5-amino-1,3,4-thiadiazole-2-thiol. The dyes were characterized by the IR spectra, electronic absorption spectra in the UV and visible regions, and 1H NMR and mass spectra. The effects of solvent nature, acidity of the medium, temperature, and concentration on the electronic absorption spectra in the visible region and the dependence of the color of the dyes on the nature of heterocyclic fragment were examined.
30 citations
TL;DR: In this paper, the X-ray diffraction and IR data showed that 2-morpholino(pyrrolidin-1-yl)methylidene-3-fluoroalkyl-3 -oxopropionates exist as Z isomers both in the crystalline state and in solution.
Abstract: Condensation of ethyl 3-polyfluoroalkyl-3-oxopropionates with excess triethyl orthoformate gave ethyl 3-polyfluoroalkyl-2-ethoxymethylidene-3-oxopropionates which reacted with primary aliphatic, aromatic, and heterocyclic amines to form ethyl 2-alkyl(aryl, hetaryl)aminomethylidene-3-polyfluoroalkyl-3-oxopropionates. According to the X-ray diffraction and IR data, the latter exist in the crystalline state as the corresponding E isomers, while in solution (NMR data), as mixtures of Z and E isomers. Condensation of ethyl 2-ethoxymethylidene-3-oxopropionates with secondary heterocyclic amines (morpholine and pyrrolidine) led to the formation of 2-morpholino(pyrrolidin-1-yl)methylidene-3-fluoroalkyl-3-oxopropionates which were shown to exist as Z isomers both in the crystalline state and in solution.
28 citations
TL;DR: The reaction of malonitrile dimer with phenyl isothiocyanate gave (6-amino-1-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-4-ylidene)malononitriles which was then used as starting material in the synthesis of pharmacologically important fused pyrimidine derivatives.
Abstract: The reaction of malononitrile dimer with phenyl isothiocyanate gave (6-amino-1-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-4-ylidene)malononitrile which was then used as starting material in the synthesis of pharmacologically important fused pyrimidine derivatives, such as 4-dicyanomethylidene-1,5-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrrolo[2,3-d]pyrimidine, 6-cyano-4-dicyanomethylidene-7-methylsulfanyl-5-oxo-1-phenyl-2-thioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine, 6-dicyanomethylidene-3-phenyl-2-thioxo-1,2,3,6-tetrahydro-9H-purine, and 6-substituted 4-dicyanomethylidene-7-oxo-1-phenyl-2-thioxo-1,2,3,4,7,8-hexahydropteridines.
24 citations
TL;DR: In this article, the synthesis of aromatic compounds with acetylene ketones in superacids occurs with the primary syn-addition of a hydrogen and an aryl residue to the acetylene bond followed by transformation of the product into anti-isomer under the conditions of the reaction.
Abstract: Vinyl type cations ArC+=CHCOR generated from acetylene ketones ArC≡CCOR in superacids HSO3F and CF3SO3H react with diverse benzene derivatives to form alkenylation products, E-/Z-isomers of diarylpropenone structures Ar(Ar’)C=CHCOR. The alkenylation of aromatic compounds with acetylene ketones in superacids occurs with the primary syn-addition of a hydrogen and an aryl residue to the acetylene bond followed by transformation of the product into anti-isomer under the conditions of the reaction.
23 citations
TL;DR: In this paper, a fusion of 4-aryl-2,4-dioxobutanoic acids and their methyl esters, respectively, with 1H-tetrazol-5-amine and aromatic aldehydes was shown to yield methyl 6-acetyl-5.hydroxy-7-(2-fluorophenyl)-4,5,6,7,tetrahydrotetrazolo[1,5-a]pyrimidine-5 carboxylate.
Abstract: 6-Acyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-5-carboxylic acids and methyl 6-acyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-5-carboxylates were synthesized by fusion of 4-aryl-2,4-dioxobutanoic acids and their methyl esters, respectively, with 1H-tetrazol-5-amine and aromatic aldehydes. The reaction of methyl 2,4-dioxopentanoate with 1H-tetrazol-5-amine and 2-fluorobenzaldehyde in boiling acetic acid gave methyl 6-acetyl-5-hydroxy-7-(2-fluorophenyl)-4,5,6,7-tetrahydrotetrazolo[1,5-a]pyrimidine-5-carboxylate.
23 citations
TL;DR: In this article, the properties of mixed phosphonium-iodonium ylides were investigated, and the compounds were shown to behave as O-nucleophiles in nucleophilic substitution reactions.
Abstract: Properties of mixed phosphonium-iodonium ylides were investigated, and the compounds were shown to be capable to behave as O-nucleophiles in nucleophilic substitution reactions.
21 citations
TL;DR: In this paper, a chiral pincer ligand having CH=N moieties was synthesized by condensation of 1H-pyrrole-2,5-dicarbaldehyde with l-methionine and l-histidine methyl esters.
Abstract: New chiral pincer ligands having CH=N moieties were synthesized by condensation of 1H-pyrrole-2,5-dicarbaldehyde with l-methionine and l-histidine methyl esters. Their reduction under mild conditions (NaBH4, −30°C) gave the corresponding amine ligands in high yields. An improved procedure for the preparation of 1H-pyrrole-2,5-dicarbaldehyde was proposed.
TL;DR: In this paper, N-Arylmethylene and N-benzhydrylideneamines react with fluorocarbene yielding fluoro-substituted azomethine ylides that undergo 1,3-π-cyclization into aziridines.
Abstract: N-Arylmethylene and N-benzhydrylideneamines react with fluorocarbene yielding fluoro-substituted azomethine ylides that undergo 1,3-π-cyclization into aziridines. Generation of fluoroylides in the presence of dipolarophiles (dimethyl maleate or dimethyl acetylenedicarboxylate) led to the reaction of 1,3-dipolar cycloaddition resulting in substituted 2-pyrrolines or pyrroles. 2-Fluoroaziridines, products of N-alkyl-N-benzhydrylideneamines 1,3-π-cyclization, in the presence of acid catalysts suffer isomerization into α-fluoroimines and 1,3-disubstituted indoles.
TL;DR: In this article, N-substituted 5-aryl-3-imino-3H-furan-2-ones with OH-and NH-nucleophiles attack the carbon atom in the position 2 of the furan ring.
Abstract: In reactions of N-substituted 5-aryl-3-imino-3H-furan-2-ones with OH-and NH-nucleophiles the nucleophilic reagents attack the carbon atom in the position 2 of the furan ring. All reactions involve the destruction of the furan system.
TL;DR: 1,3-Diiodo-5,5-dimethylhydantoin in organic solvents successfully iodinates alkylbenzenes, aromatic amines, and phenyl ethers and readily reacts with electron-deficient arenes at 0 to 20°C with formation of the corresponding iodo derivatives in good yields.
Abstract: 1,3-Diiodo-5,5-dimethylhydantoin in organic solvents successfully iodinates alkylbenzenes, aromatic amines, and phenyl ethers. The reactivity of electrophilic iodine is controlled by acidity of the medium. Superelectrophilic iodine generated upon dissolution of 1,3-diiodo-5,5-dimethylhydantoin in sulfuric acid readily reacts with electron-deficient arenes at 0 to 20°C with formation of the corresponding iodo derivatives in good yields. The structure of electrophilic iodine species generated from 1,3-diiodo-5,5-dimethylhydantoin in sulfuric acid is discussed.
TL;DR: In this article, the synthesis of compounds containing two bis(1H-pyrazol-1-yl)methane fragments has been studied and new approaches have been proposed.
Abstract: New approaches have been proposed for the synthesis of compounds containing two bis(1H-pyrazol-1-yl)methane fragments. Nucleophilic replacement of the halogen atoms in appropriate tetrabromo derivatives by pyrazoles in the superbasic system KOH-DMSO gave ditopic chelating ligands: 1,1,2,2-tetrakis(1H-pyrazol-1-yl)ethane, 1,4-bis[bis(1H-pyrazol-1-yl)methyl]benzene, and 1,4-bis[bis(3,5-dimethyl-1H-pyrazol-1-yl)methyl]benzene. 1,4-Bis[bis(1H-pyrazol-1-yl)methyl]benzene was also synthesized by reaction of 1H-pyrazole with terephthalaldehyde in the presence of thionyl chloride. 1,1,2,2-Tetrakis(1H-pyrazol-1-yl)ethane was converted into the corresponding tetraiodo and tetranitro derivatives.
TL;DR: In this paper, the authors summarized and analyzed the methods for modification of protoporphyrin IX and its derivatives, focusing on those transformations which are important from the practical viewpoint for the preparation of compounds possessing valuable medical, biological, and physical properties, as well as specific transformations inherent to the tetrapyrrole macroring.
Abstract: Numerous recently published data on the methods for modification of protoporphyrin IX and its derivatives have been summarized and analyzed. Special attention has been given to those transformations which are important from the practical viewpoint for the preparation of compounds possessing valuable medical, biological, and physical properties, as well as to specific transformations inherent to the tetrapyrrole macroring.
TL;DR: In this paper, the molecular and crystalline structure of the 1-cyclohexyl-substituted derivative was studied by X-ray analysis, and the structure was shown to have a 1.
Abstract: 3-Aroyl-2,4-dihydro-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones react with N-unsubstituted and N-substituted 3-amino-5,5-dimethylcyclohex-2-en-1-ones to give 3′-aroyl-4′-hydroxy-1′-(o-hydroxy-phenyl)-6,6-dimethyl-6,7-dihydrospiro[indole-3,2′-pyrrole]-2,4,5′(1H,1′H,5H)-triones. The molecular and crystalline structure of the 1-cyclohexyl-substituted derivative was studied by X-ray analysis.
TL;DR: In this article, N-iodosuccinimide in sulfuric acid gives rise to electrophilic iodine-containing species which are capable of successfully iodinating aromatic compounds with electron-withdrawing substituents in the temperature range from 0 to 20°C.
Abstract: Dissolution of N-iodosuccinimide in sulfuric acid gives rise to electrophilic iodine-containing species which are capable of successfully iodinating aromatic compounds with electron-withdrawing substituents in the temperature range from 0 to 20°C. The iodination in sulfuric acid is effected by both protonated N-iodosuccinimide and IOS(O)(OH+)OH intermediate.
TL;DR: Schiff bases generated in situ from substituted anilines and 2-allyloxybenzaldehyde underwent acid-catalyzed intramolecular Diels-Alder reaction followed by dehydrogenation to give 6H-chromeno[4,3-b]-quinolines as discussed by the authors.
Abstract: Schiff bases generated in situ from substituted anilines and 2-allyloxybenzaldehyde underwent acid-catalyzed intramolecular Diels-Alder reaction followed by dehydrogenation to give 6H-chromeno[4,3-b]-quinolines. Under analogous conditions, derivatives of 2-allyloxynaphthalene-1-carbaldehyde were converted into 8a,9,14,14a-tetrahydro-8H-benzo[5,6]chromeno[4,3-b]quinolines. Possible dehydrogenation mechanisms are discussed.
TL;DR: In this article, the reaction of 1-methyl-1-phenyl-2-diphenylvinylidenecyclopropane with N-benzylideneanilines in the presence of BF3·Et2O, Yb(OTf)3, or Sc(OT)3 lead to the formation of substituted 1,2,3,4-tetrahydroquinolines.
Abstract: 1-Methyl-2-(2-methylpropenylidene)-1-phenylcyclopropane, 7-(2-methylpropenylidene)bicyclo[4.1.0]heptane, and (Z)-9-(2-methylpropenylidene)bicyclo[6.1.0]non-4-ene react with N-benzylideneanilines in the presence of boron trifluoride-ether complex to give pyrrolidine derivatives. Reactions of 1-methyl-1-phenyl-2-diphenylvinylidenecyclopropane with N-benzylideneanilines in the presence of BF3·Et2O, Yb(OTf)3, or Sc(OTf)3 lead to the formation of substituted 1,2,3,4-tetrahydroquinolines. 7-Diphenylvinylidenebicyclo[4.1.0]heptane in the presence of BF3·Et2O undergoes isomerization into 5-phenyl-8,9,10,11-tetrahydro-7H-cyclohepta[a]naphthalene.
TL;DR: In this paper, a review analyzes main tendencies in the development of modern methods for estimation of reactivity of organic compounds and reaction regioselectivity, including correlation analysis, reactivity descriptors, QSPR, and other methods.
Abstract: The review analyzes main tendencies in the development of some modern methods for estimation of reactivity of organic compounds and reaction regioselectivity. The up-to-date correlation analysis, reactivity descriptors, QSPR, and other methods are compared with respect to their advantages and disadvantages.
TL;DR: In this paper, fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-diketones) were synthesized by azo coupling of the corresponding 1,3dicarbonyl compounds with biphenyl 4,4-bis(diazonium) dichloride.
Abstract: New fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-diketones) and 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(3-oxopropionates) were synthesized by azo coupling of the corresponding 1,3-dicarbonyl compounds with biphenyl-4,4′-bis(diazonium) dichloride. Complexing ability of the obtained bis-hydrazones was studied, and new coordination compounds of the general formula M2L2 [where M = Ni(II), Cu(II); L = fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-diketone)] were obtained.
TL;DR: In this article, 3,4,6-trisubstituted pyridazines were synthesized from fluoroalkyl-containing diazo keto esters in three steps along two different reaction sequences.
Abstract: 3,4,6-Trisubstituted pyridazines were synthesized from fluoroalkyl-containing diazo keto esters in three steps along two different reaction sequences: (1) Wittig, Staudinger, and diaza-Wittig and (2) Staudinger, Wittig, and diaza-Wittig. According to the first of these with the initial Wittig reaction, the yield of the target 4-fluoroalkyl-substituted pyridazines is almost twice as large as in the reaction sequence involving the corresponding N-phosphanylidene derivatives as intermediates. In both sequences, the final steps (synthesis of vinylphosphazenes and the subsequent diaza-Wittig reaction) occurred as a tandem process, and intermediate vinylphosphazenes could not be isolated. Non-fluorinated diazo keto esters and the respective phosphazenes failed to react with alkoxycarbonylmethylidene(triphenyl)phosphoranes under the same conditions.
TL;DR: Cyclomagnesation of α,ω-diallenes by EtMgBr in the presence of chemically activated Mg and Cp2TiCl2 catalyst led to the formation of cyclic organomagnesium compounds whose hydrolysis provided gigantic hydrocarbon macrorings with 1,5-cis-disubstituted double bonds.
Abstract: Cyclomagnesation of α,ω-diallenes by EtMgBr in the presence of chemically activated Mg and Cp2TiCl2 catalyst led to the formation of cyclic organomagnesium compounds whose hydrolysis provided gigantic hydrocarbon macrorings with 1,5-cis-disubstituted double bonds.
TL;DR: In this paper, it was shown that 1,3-Diacetoxytetramethyldisiloxane is formed in the reaction of acyl iodide with dimethoxy(dimethyl)silane.
Abstract: Reactions of acyl iodides RCOI (R = Me, Ph) with organosilicon compounds involve cleavage of the Si-O-C and Si-O-Si fragments. Acetyl iodide reacts with alkyl(alkoxy)silanes with evolution of heat, and cleavage of the Si-O bond results in the formation of oligo-or polysiloxanes, alkyl iodides, and alkyl acetates. 1,3-Diacetoxytetramethyldisiloxane is formed in the reaction of acetyl iodide with dimethoxy(dimethyl)silane. Acyl iodides readily react with 1-ethoxysilatrane to give 1-acyloxysilatranes as a result of cleavage of the C-O bond. The reaction of acetyl iodide with hexaethyldisiloxane yields triethylsilyl acetate and triethyliodosilane, while in the reaction with octamethyltrisiloxane iodo(trimethyl)silane and dimethyl(trimethylsiloxy)silyl acetate are obtained.
TL;DR: In this article, 4-Aryl(alkyl)iminomethyl, 5-hydroxy-6-nitro-2,3-diphenyl-1-benzofuran-4-carbaldehyde imine having a benzo-15-crown-5 fragment on the nitrogen atom is shown to exist in solution as equilibrium mixtures of benzoid and quinoid tautomers.
Abstract: 4-Aryl(alkyl)iminomethyl-5-hydroxy-and 4-aryl(alkyl)iminomethyl-5-hydroxy-6-nitro-2,3-diphenyl-1-benzofurans were synthesized and were shown to exist in solution as equilibrium mixtures of benzoid and quinoid tautomers. The fraction of the quinoid form increases with rise in the solvent polarity and in going from N-aryl to N-alkyl derivatives; introduction of an electron-acceptor substituent (nitro group) into the 6-position of the benzofuran system also favors formation of the quinoid tautomer. Complex formation of alkali and alkaline-earth metal cations with the 5-hydroxy-6-nitro-2,3-diphenyl-1-benzofuran-4-carbaldehyde imine having a benzo-15-crown-5 fragment on the nitrogen atom is accompanied by specific changes in the luminescence spectrum and in the state of tautomeric equilibrium, so that this system may be regarded as tautomeric fluorogenic chemosensor for metal cations.