<Emphasis Type="Italic">N</Emphasis>-(3-Phosphonopropyl)-substituted α-amino acids and their phosphine oxide analogs

A facile method was developed for the synthesis of N-(3-phosphonopropyl)-substituted α-amino acids and their phosphine oxide analogs based on hydrolysis of 2-oxo-1,2-azaphospholanes and 1,2-azaphospholanium salts prepared from readily available reagents. A chelate Cu^II N-[(3-diphenylphosphoryl)propyl]glycinate was isolated. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2551–2556, November, 2005.     

Preparative synthesis of the Corey chiral controller for enantioselective dihydroxylation of olefins

A five-step synthesis of both enantiomers of 1,2-di(2,4,6-trimethylbenzylamino)-1,2-diphenylethane,i.e., Corey (R,R)- and (S,S)-controllers for enantioselective dihydroxylation of olefins by osmium tetroxide, starting from α,α′-diphenylglyoxime, has been developed. The key operations in the synthesis are the optical resolution of intermediaterac-1,2-diamino-1,2-diphenylethane into two enantiomers using only (R,R)-tartaric acid and the subsequent enhancement of the enantiomeric purity to >98% by crystallizations of the corresponding Schiff's bis-bases. Analysis of the enantiomeric purity of the controllers can be easily performed using¹H NMR spectra of their salts with (R)-α-methoxy-α-(trifluoromethyl)phenylacetic acid (MosherR-acid). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 101–105, January, 1997.     

Synthesis of 5-mercapto-1,2-dithiole-3-thiones and their transformation into 5-chloro-1,2-dithiol-3-ones

A number of 4-dialkylamino-5-mercapto-1,2-dithiole-3-thiones were synthesized by reactions of alkyl(diisopropyl)amines with S₂Cl₂. Their reactions with S₂Cl₂—DABCO unexpectedly gave 5-chloro-4-dialkylamino-1,2-dithiol-3-ones. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 143–147, January, 2006.     

A reaction of 6-bromo-1,2-naphthoquinone with tri(<Emphasis Type="Italic">n</Emphasis>-butyl)phosphine: A convenient route to phosphorus-containing 1,2-naphthoquinones and 1,2-dihydroxynaphthalenes

A reaction of 6-bromo-1,2-naphthoquinone with tri(n-butyl)phosphine gave 2-hydroxy-4-tri(n-butyl)phosphonionaphth-1-olate (betaine with the P—C bond). When treated with bromine, this betaine changed into (6-bromo-1,2-dihydroxy-4-naphthyl)tri(n-butyl)phosphonium bromide and (6-bromo-1,2-dioxo-1,2-dihydro-4-naphthyl)tri(n-butyl)phosphonium bromide in the ratio ∼1: 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 534–536, March, 2007.     

Synthesis of Enantiopure Chiral Perhydrobenzimidazole and Hexahydroquinoxaline Derivatives

Summary.  Starting from 2-anilino-2-ethoxy-3-oxothiobutyric acid anilides and (R, R)-or (S, S)-trans-1,2-diaminocyclohexane, chiral C2-disubstituted perhydrobenzimidazole and trans-4a,5,6,7,8,8a-hexahydroquinoxaline derivatives were obtained depending on the polarity of the solvent. Received April 10, 2000. Accepted May 2, 2000     

The investigations in 2,3′-biquinoline series. 25*. Synthesis of 4-(2-quinolinyl)-pyrrolo[1,2-<Emphasis Type="Italic">a</Emphasis>]quinolines and 4-(2-quinolyl)-imidazo[1,2-<Emphasis Type="Italic">a</Emphasis>]quinolines

A method has been developed for the synthesis of 4-(2-quinolinyl)-1,2,3,3a-tetrahydropyrrolo-[1,2-a]quinolines based on the 1,3-dipolar cycloaddition reaction of α,β-unsaturated carbonyl compounds to 2,3′-biquinolinium salts. Oxidation in benzene using MnO₂ gave 4-(2-quinolinyl)-pyrrolo[1,2-a]quinolines. It was found that a side product of the 1,3-dipolar cycloaddition is 7,14-di-benzoyl-6,13-di(2-quinolyl)-6a,7,13a,14-tetrahydro-7a,14a-diazadibenzo[a,h]anthracene. Reaction of 1′-phenacyl-2,3′-biquinolinium salts with hydroxylamine in acetic acid gave 4-(2-quinolyl)imidazo-[1,2-a]quinolines. *For Communication 24 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 433–439, March, 2009.     

Nitroxide Radicals of some N-Phenyl Substituted 1,4- and 1,2-Phenylenediamines

Summary.  Several N-phenyl substituted 1,4- and 1,2-phenylenediamines were oxidized using radicals and 3-chloroperbenzoic acid. EPR spectroscopy confirmed the generation of nitroxide radicals originating from the oxidation of the bridging -NH-group. No radical products suggesting the simultaneous reaction with the NH₂-group were observed. Only in the case of 1,4-phenylenediamine, a low concentration of nitroxide radical H–NO–C₆H₄–NH₂ was obtained. In o-aminodiphenylnitroxide the steric effect of the NH₂-group causes a partially asymmetrical spin density distribution in both phenyl rings. Corresponding author. E-mail: omelka@fch.vutbr.cz Received September 30, 2002; accepted October 4, 2002     

Synthesis of substituted 7,8-di(propylsulfonyl)pyrrolo[1,2-<Emphasis Type="Italic">a</Emphasis>]pyrazines

Heating of pyrazinium salts with E-1,2-dichloro-1,2-di(propylsulfonyl)ethene in chloro-form in the presence of three-fold excess of Et₃N regiospecifically gives rise to substituted 7,8-di(propylsulfonyl)pyrrolo[1,2-a]pyrazines in high yields. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 424–426, February, 2008.     

Reactions of 3-hydroxy-1,2-dihydroquinazolin-4-ones with acid chlorides

The reactions of 3-hydroxy-1,2-dihydroquinazolin-4-ones with acid chlorides can afford compounds of different types. The structures of the products depend on the type of acid chloride used and on the nature of the substituent at position 2 of the 3-hydroxy-1,2-dihydroquinazolin-4-one. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1346–1349, July, 1999.     

Study of the Dependence on Temperature and Composition of the Volumic Properties of Ethane-1,2-diol + 2-Methoxyethanol + 1,2-Dimethoxyethane + Water Solvent System and Graphical Representation in the Quaternary Domain

In this paper, the temperature and composition dependencies of the volumetric behavior are studied for the ethane-1,2-diol + 2-methoxyethanol + 1,2-dimethoxyethane + water quaternary system. Density data were collected at different temperatures ranging from −10 to 80 ^∘C and at atmospheric pressure over the whole composition range, 0≤ x_i(i = 1, 2, 3, 4)≤ 1. Moreover, we also made use of the results on the six binary (ij) and four ternary (kij) subsystems studied previously. The excess molar volume (V^E) data have been fitted to an equation derived from the well-known Redlich–Kister equation and some interesting correlations were found. Furthermore, in order to represent in an effective way the behavior of the V^E = V^E(x_i) function (and of the derived partial molar quantities) in the quaternary domain, a new algorithm has been developed, which gives 3D plots where the dependent function is depicted by means of “colored slices” of the tetrahedron corresponding to the investigated composition quaternary domain.     

Synthesis of aliphatic 1,2-bishydroxylamines from 1,3- dihydroxyimidazolidines.

Reduction of l-hydroxy-3-imidazoline-3-oxides with NaBH₄ gives 1,3-dihydroxyimidazolidines. The latter on subsequent treatment with NH₂OH · HCl in EtOH or in hydrochloric acid afford 1,2-bishydroxylamines. An X-ray study of 1,2-bishydroxylaminocycloalkanes has shown them to becis-configurated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 896–901, May, 1993.     

Novel <Emphasis Type="Italic">S</Emphasis>-containing lactones from monoterpene oxides

A new type of S-containing terpene lactones was produced by the reactions of limonene-1,2-oxide and β-pinene-α-oxide with mercaptoacetic acid. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 220–223, May–June, 2007.     

顺、反-1,2-环己二胺对有机-无机杂化锑碘异构体的影响

在浓氢碘酸水溶液中,顺式和反式-1,2-环己二胺(DAC)分别与三碘化锑反应得到2种有机-无机杂化异构体(cis-1,2-DACH_2)[SbI_5]·H_2O(1)和{(trans-1,2-DACH_2)[SbI_5]·H_2O}_n(2)。X射线单晶衍射表明化合物1中的无机成分是由2个[SbI_6]八面体通过共I-I边形成的二聚体[Sb_2I_(10)],而化合物2中的无机部分是[SbI_6]八面体通过共享顶点形成的一维锯齿链。此外,利用紫外-可见光谱、荧光光谱和密度泛函理论对化合物1和2进行了比较研究。     

Theoretical predictions of the structure, gas-phase acidity and aromaticity of 1,2-diseleno-3,4-dithiosquaric acid

Results of ab initio self-consistent-field (SCF) and density functional theory (DFT) calculations of the gas-phase structure, acidity (free energy of deprotonation, ΔG^o), and aromaticity of 1,2-diseleno-3,4-dithiosquaric acid (3,4-dithiohydroxy-3-cyclobutene-1,2-diselenone, H₂C₄Se₂S₂) are reported. The global minimum found on the potential energy surface of 1,2-diseleno-3,4-dithiosquaric acid presents a planar conformation. The ZZ isomer was found to have the lowest energy among the three planar conformers and the ZZ and ZE isomers are very close in energy. The optimized geometric parameters exhibit a bond length equalization relative to reference compounds, cyclobutanediselenone, and cyclobutenedithiol. The computed aromatic stabilization energy (ASE) by homodesmotic reaction (Eq 1) is −20.1 kcal/mol (MP2(fu)/6-311+G** //RHF/6-311+G**) and −14.9 kcal/mol (B3LYP//6-311+G**//B3LYP/6-311+G**). The aromaticity of 1,2-diseleno-3,4-dithiosquaric acid is indicated by the calculated diamagnetic susceptibility exaltation (Λ) −17.91 (CSGT(IGAIM)-RHF/6-311+G**//RHF/6-311+G**) and −31.01 (CSGT(IGAIM)-B3LYP/6-311+G**//B3LYP/6-311+G**). Thus, 1,2-diseleno-3,4-dithiosquaric acid fulfils the geometric, energetic and magnetic criteria of aromaticity. The calculated theoretical gas-phase acidity is ΔG^o _1(298K)=302.7 kcal/mol and ΔG^o _2(298K)=388.4 kcal/mol. Hence, 1,2-diseleno-3,4-dithiosquaric acid is a stronger acid than squaric acid(3,4-dihydroxy-3-cyclobutene-1,2-dione, H₂C₄O₄). Received: 11 April 2000 / Accepted: 7 July 2000 / Published online: 27 September 2000     

Intercalation of 1,2-Alkanediols into α-Zirconium Hydrogenphosphate

Intercalation compounds of α-Zr(HPO₄)₂ · H₂O with 1,2-alkanediols (from C3 to C16) have been prepared by replacing 1-propanol in α-Zr(HPO₄)₂ · 2C₃H₇OH with the desired 1,2-alkanediols by a treatment in a microwave field. It was found that the intercalates contain 1.5 molecules of diol per formula unit. The diol molecules are placed between the host layers in a bimolecular way with their aliphatic chains tilted at an angle of 51°. The diol molecules are anchored in the interlayer space by H-bonds. A mixed intercalate, containing 1,2-butanediol and 1,2-decanediol in a roughly equimolar ratio, is formed when the α-Zr(HPO₄)₂ · 2C₃H₇OH intercalate, suspended in a mixture of 1,2-butanediol and 1,2-decanediol, is exposed to microwave radiation. No new phase containing both types of the guest molecules was observed when the 1-propanol intercalate, suspended in a mixture of 1-propanol and 1,2-octanediol, is exposed to microwave radiation.     

Synthesis and study of new 2-aryl-1-(4-nitrophenyl)-1,1a-dihydroazireno[1,2-a]quinoxaline derivatives

New derivatives of photochromic 2-aryl-1-(4-nitrophenyl)-1,1a-dihydroazireno[1,2-a]quinoxalines were synthesized by condensation of 4-methyl-and 4,5-dimethyl-1,2-phenylenediamine with 1,3-diaryl-2,3-dibromopropan-1-ones. The reactions of 4-methyl-1,2-phenylenediamine produce mixtures of regioisomers. The chemical properties of the reaction products were studied. The structure of one of the latter was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 350–356, February, 2006.     

Trisodium heptaphosphide in reactions with cyclopropenyl complexes of nickel

Reactions of trisodium heptaphosphide with half-sandwich cyclopropenyl complexes of nickel gave sodium 1,2-diphosphacyclopentadienide. The influence of the ligand environment of the nickel atom on the formation of sodium 1,2-diphosphacyclopentadienide was studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 294–296, February, 2007.     

New catalytic system for the synthesis of imidazo[1,2-a]pyridines by the Ugi reaction

A combination of N-hydroxysuccinimide and p-toluenesulfonic acid is proposed as an efficient catalyst for the preparation of a great variety of imidazo[1,2-a]pyridine derivatives by three-component condensation of aromatic isocyanides, aldehydes, and 2-aminopyridine. The advantages of this procedure are high yields of the target products and the absence of side reactions. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1768–1772, October, 2006.     

Reaction of Z isomers of alkylaromatic 1,2-hydroxylamino oximes with 1,2-diketones

The reactions of Z isomers of alkylaromatic 1,2-hydroxylamino oximes containing the hydroxylamino group at the primary or secondary carbon atom with diacetyl afford 6-acetyl-5,6-dihydro-4H-1,2,5-oxadiazines. The reactions of these compounds with alkylaromatic 1,2-diketones produce N-substituted α-aroylnitrones or 6-aroyl-5,6-dihydro-4H-1,2,5-oxadiazines or, alternatively, their tautomeric mixtures. Dedicated to the memory of Academician V. A. Koptyug on the occasion of the 75th anniversary of his birth. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1008–1013, June, 2006.     

Electrochemical transformation of cyanoacetic ester and alkylidenecyanoacetic esters into 3-substituted 1,2-dicyanocyclopropane-1,2-dicarboxylates

Electrolysis of cyanoacetic ester and alkylidenecyanoacetic esters in an undivided cell in the presence of mediators (alkali metal halides) gives rise to 3-substituted, 1,2-dicyanocyclopropane-1,2-dicarboxylates in 60–95% yields. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1165–1168, June, 1998.