Showing papers in "Russian Chemical Bulletin in 1984"
TL;DR: In this paper, the effect of substituents in the aromatic ligands of the iodoniura salts on their reactivity is retained on going over from homogeneous media to a two-phase system.
Abstract: 1.
Arylation of anions by diarylhalonium fluoroborates under conditions of interphase catalysis proceeds more rapidly than in homogeneous media and as a rule in higher yield of the desired products.
2.
The rules for the influence of substituents in the aromatic ligands of the iodoniura salts on their reactivity are retained on going over from homogeneous media to a two-phase system.
3.
The yield of O-phenylation products grew in the series\(Ph_2 \mathop I\limits^ +< Ph_2 \mathop {Br}\limits^ +< Ph_2 \mathop {Cl}\limits^ + \) in the reaction of diphenylhalonium cations with the benzenesulfinate anion.
23 citations
TL;DR: A new complexone, 1,4,7,10,tetrakis (dihydroxyphosphorylmethyl)-1, 4, 7, 10-tetraazacyclododecane, has been synthesized and its acid-base and complex-forming properties have been studied as discussed by the authors.
Abstract: A new complexone, 1,4,7,10-tetrakis(dihydroxyphosphorylmethyl)-1,4,7,10-tetraazacyclododecane, has been synthesized and its acid-base and complex-forming properties have been studied. It shows a very high complexing capability and marked selectivity for cations of large ionic radius (Cd2+, Hg2+, Pb2+, La3+).
18 citations
TL;DR: In this paper, the vibrational frequencies of the free allyl radical C3D5 have been obtained for the first time, and the bands assigned to the normal vibrations have been derived.
Abstract: 1.
By the technique of matrix isolation of products from the vacuum pyrolysis of 1,5-hexadiene-d10, the IR spectrum of the free allyl radical C3D5 has been obtained for the first time.
2.
On the basis of the IR spectra of the C3H5 and C3D5 radicals, vibrational frequencies of the allyl radical have been calculated, and the bands have been assigned to the normal vibrations.
3.
A systematic comparison has been made of the vibrational frequencies of the allyl radical and the Π-allyl ligand in the composition of organometallic compounds. It has been established that the frequencies of out-of-plane vibrations ρw(CH2), ρt(CH2), and ρ(CH) are substantially higher for the Π-allyl ligand; the frequencies of vibrations taking place in the plane of the allyl fragment are little different for the two cases. A new assignment has been proposed for a number of frequencies in the spectra of Π-allyl complexes.
4.
The system of bonds
for the allyl radical is characterized by relatively low frequencies of stretching vibrations and the force constant
5. 8 mdyne/A. The values of νs(CCC) and νas(CCC) show that upon formation of a Π-allyl complex, there is no loosening of the carbon-carbon bonds of the ligand, in contrast to Π-complexes of unsaturated compounds.
14 citations
TL;DR: In this paper, a new complexone, N,N′,N″-tris(dihydrophosphorylmethyl)-1,4,7-triazacyclononane, was synthesized, which is distinguished by a high complex-forming capability and considerable selectivity.
Abstract: 1.
We have synthesized a new complexone, N,N′,N″-tris(dihydrophosphorylmethyl)-1,4,7-triazacyclononane that is distinguished by a high complex-forming capability and considerable selectivity.
2.
The new compound shows a hitherto unobserved selectivity for magnesium over calcium, and for zinc over cadmium and the 3-d transition metals.
14 citations
TL;DR: In this paper, the synthesis of a series of 5-arylethynyl-1,4-naphthoquinones was carried out by the reaction of five-iodonaphthoequinone with substituted cuprous acetylides.
Abstract: The syntheses of a series of 5-arylethynyl-1,4-naphthoquinones were carried out by the reaction of 5-iodonaphthoquinone with substituted cuprous acetylides.
12 citations
TL;DR: The cyclopropanation of olefins proceeds through a step involving the reaction of diazomethane with a Π-olefinic complex of zero-valent palladium formed upon the reduction of the palladium compounds introduced as the catalyst by diazmethane as discussed by the authors.
Abstract: 1.
In the cyclopropanation of mono- and polyolefins by diazomethane in the presence of palladium compounds, strained intracyclic and terminal double bonds are initially cyclopropanated with high selectivity.
2.
The cyclopropanation of olefins proceeds through a step involving the reaction of diazomethane with a Π-olefinic complex of zero-valent palladium formed upon the reduction of the palladium compounds introduced as the catalyst by diazomethane.
11 citations
8 citations
8 citations
TL;DR: In this article, the general principles of nonideal chromatography for linear, concave, and convex sorption isotherms were examined based on the equilibrium adsorption layer model.
Abstract: 1.
The general principles of nonideal chromatography for linear, concave, and convex sorption isotherms were examined based on the equilibrium adsorption layer model.
2.
The outlet time of the peak maximum in linear chromatography does not coincide with the outlet time calculated from the well-known ratio between the retention time and the volume retained for a value equal to HLe/v.
3.
The outlet elution curves for any isotherms with a length of the chromatographic column close to the equilibrium adsorption layer is a diminishing function.
4.
As the length of the chromatographie column increases, parallel transfer of the rear boundaries of the outlet curves is observed for any isotherms.
7 citations
TL;DR: The spectral and kinetic properties of the photoinduced colored species in a solution of 6-nitrospiropyrans in hexane are determined by associates of colored and colorless species.
Abstract: 1.
The spectral and kinetic properties of the photoinduced colored species in a solution of 6-nitrospiropyrans in hexane are determined by associates of colored and colorless species.
2.
The spectral bands at 580 and 615 nm belong to associates of the monomeric colored and colorless state of type BB and AB, the band at 520–540 nm belongs to the associate of the dimer of the colorless state of type ABA2, and the state with charge transfer (A+B−)An, formed in the reaction of ABA2 with the colorless state, is responsible for the absorption band at 670 nm.
3.
The highly polar state (A+B−)An, which takes up other states, forms high-molecular associates.
4.
The thermal decolorization of states AB, BB, and ABA2 takes place one order of magnitude more rapidly than that of state (A+B−)An.
5.
The bulky alkyl substituent on the nitrogen atom in spiropyran hinders association of the colorless form and the formation of associate ABA2 and creates additional hindrances to the reaction of decolorization in the state of isomerization and cyclization.
7 citations
TL;DR: In this paper, the authors carried out the oxidative addition of acetylacetone, ethyl acetoacetate, diethyl malonate to ethylene, 1hexene, and cyclohexene using Mn(III) acetate in the presence of LiCl, leading to the predominant formation of either mono- or dichloroadducts depending on the structure of the carbonyl compound and the olefin.
Abstract: 1.
We carried out the oxidative addition of acetylacetone, ethyl acetoacetate, diethyl malonate to ethylene, 1-hexene, and cyclohexene using Mn(III) acetate in the presence of LiCl, leading to the predominant formation of either mono- or dichloroadducts depending on the structure of the carbonyl compound and the olefin.
2.
1,1-Difunctional cyclopropanes were obtained from the chloro derivatives synthesized.
TL;DR: In this paper, the Mn(OAc)3-LiCl system was used for the addition of chloromalonic esters to 1-hexene, 1-hexyne, norbornene, acrylonitrile, and methyl acrylate.
Abstract: The oxidative addition of chloromalonic ester to 1-hexene, 1-hexyne, norbornene, acrylonitrile, and methyl acrylate has been carried out under the influence of the Mn(OAc)3-LiCl system. It yields functionally substituted 1,3-dichlorides that are used for the synthesis of substituted 1,1-diethoxycarbonylcyclopropanes.
TL;DR: In this paper, the kinetics of neutral hydrolysis of 1-organyl and 1-alkoxyl silatranes in a neutral medium was studied by UV spectroscopy.
Abstract: 1
The kinetics of hydrolysis of 1-organyl- and 1-alkoxylsilatranes in a neutral medium was studied by UV spectroscopy
2
A scheme has been proposed for the neutral hydrolysis of silatranes with the formation of a four-centered intermediate at the first stage, followed by slow opening of the silatrane skeleton
TL;DR: In this paper, a method has been developed for the synthesis of hexaalkyl-and hexaaryl-distannanes by the dehydrogenation of R3SnH in the presence of catalytic amounts of Pd complexes.
Abstract: 1.
A convenient method has been developed for the synthesis of hexaalkyl- and hexaaryl-distannanes by the dehydrogenation of R3SnH in the presence of catalytic amounts of Pd complexes.
2.
The reaction of hexaalkyldistannanes with organic halides has been studied under conditions of catalysis with Pd complexes. A method has been developed for the synthesis of aryltrialkylstannanes with active electron-accepting substituents in the aromatic ring.
TL;DR: In this article, the pyranose radicals are formed with localized unpaired electrons in positions 1 and 4 of the Pyranoses ring, the formation of which is accompanied by the rupture of the glycoside bond.
Abstract: 1
On gamma irradiation of cellulose radicals are formed with localized unpaired electrons in positions 1 and 4 of the pyranose ring, the formation of which is accompanied by rupture of the glycoside bond
2
Thermal transformations of these radicals cause their degradation and take place with formation of allyl type radicals
TL;DR: The reaction of phthalonitrile condensation with m-phenylenediamine is thermodynamically allowed at temperatures from 250° to 500°K, and its equilibrium is almost completely shifted toward the formation of the macroheterocycle.
Abstract: The reaction of phthalonitrile condensation with m-phenylenediamine is thermodynamically allowed at temperatures from 250° to 500°K, and its equilibrium is almost completely shifted toward the formation of the macroheterocycle.
TL;DR: 3-Formyl-2-acetylenyl-1-methylindole oximes readily undergo intramolecular heterocyclization with closure of a pyridine ring and formation of substitutedγ-carboline N-oxides as discussed by the authors.
Abstract: 3-Formyl-2-acetylenyl-1-methylindole oximes readily undergo intramolecular heterocyclization with closure of a pyridine ring and formation of substitutedγ-carboline N-oxides.
TL;DR: In this paper, a system of parameters was developed which permits estimating the heat capacity of liquid organic compounds at different temperatures based on the temperature dependence of the group contributions, and the system was used to estimate the group contribution at different temperature levels.
Abstract: A system of parameters was developed which permits estimating the heat capacity of liquid organic compounds at different temperatures based on the temperature dependence of the group contributions.
TL;DR: In this article, the reaction of vinylidenediphosphonic acid with primary aliphatic amines, ammonia, and hydrazine has been studied under ambiguous reaction conditions.
Abstract: The reaction of vinylidenediphosphonic acid with primary aliphatic amines, ammonia, and hydrazine has been studied under ambiguous reaction conditions. Chromatography on a strongly acidic cation exchanger has been proposed for the separation of the reaction mixtures obtained.
TL;DR: In this article, the reaction of bis[lithium(o-carboranyl)]dimethylsilane with α, α′-dipyridyldichloride complexes of Ni, Co, Pd, and Cu gave heterocycles containing a silicon atom, four carbon atoms of two ocarborane systems and a transition metal in the ring.
Abstract: The reaction of bis[lithium(o-carboranyl)]dimethylsilane with α, α′-dipyridyldichloride complexes of Ni, Co, Pd, and Cu gave heterocycles containing a silicon atom, four carbon atoms of two o-carborane systems and a transition metal in the ring. These compounds were more stable than the corresponding acyclic o-carborane σ-complexes.
TL;DR: The case in which a stable radical is formed as a result of elimination constitutes an exception as discussed by the authors, where the acceptors contributing to radical elimination are atoms of metals, organometallic and organic radicals, and neutral molecules.
Abstract: 1.
Disappearance of the free valence in organometallic derivatives of o-semiquniones with IVB group metals linked with elimination of one of the radicals on the IVB group element, proceeds by a bimolecular mechanism with participation of an external acceptor of the radical. The case in which a stable radical is formed as a result of elimination constitutes an exception.
2.
Examples of acceptors contributing to radical elimination are atoms of metals, organometallic and organic radicals, and neutral molecules.
TL;DR: In this article, a method was proposed for the synthesis of 1,5-dienes by the reaction of allyltrimethylstannanes generated in situ with allyl acetates and allyl halides in the presence of palladium complexes.
Abstract: 1.
A method was developed for the synthesis of allyltrimethylstannanes with high yields by the reaction of Me6Sn2 with allyl acetates catalyzed by Pd(PPh3)4 and with allyl halides catalyzed by (η3-C3H5PdCl)2 in HMPTA at about 20°C.
2.
A study of the stoichiometric reaction of Me6Sn2 with the complex [η3-C3H5Pd(PPh23)2]+C1− indicated the participation of a Π-allylpalladiumintermediate in the catalytic reactions.
3.
A method was proposed for the synthesis of 1,5-dienes by the reaction of allyltrimethylstannanes generated in situ with allyl acetates and allyl halides in the presence of palladium complexes.
TL;DR: In this article, a few examples of cycloaddition to acetylene and symmetrically disubstituted alkynes had been described, which did not allow judging the characteristics of the reaction such as the limits of applicability and the structural direction, which are important for synthesis.
Abstract: Photochemical cycloaddition of ~,B-enones to alkenes and alkynes is one of the most important methods of constructing cyclic systems in modern organic synthesis. The mechanism and fields of application of this reaction have been intensively studied since 1964 (see surveys in [1-4]). The overwhelming majority of the studies have concerned reactions of ~,Benones with olefin suDstrates, for which the general features of the mechanisms of the structural [5] and steric [6] directions of cycloaddition have been established. Until our studies began, only a few examples of cycloaddition to acetylene and symmetrically disubstituted alkynes had been described [7-16], which did not allow judging the characteristics of the reaction such as the limits of applicability and the structural direction, which are important for synthesis~
TL;DR: A new method of synthesis of 6-hydroxy-4-methyl-3-cyanopyridin-2[1H]thione has been developed which consists of the reaction of β-morpholinoethylcrotonate or its corresponding anilide with cyanothioacetamide as mentioned in this paper.
Abstract: 1.
A new method of synthesis of 6-hydroxy-4-methyl-3-cyanopyridin-2[1H]thione has been developed which consists of the reaction ofβ-morpholinoethylcrotonate or its corresponding anilide with cyanothioacetamide.
2.
6-Hydroxy-4-methyl-3-cyanopyridin-2[1H]thione is selectively alkylated at the sulfur atom.
TL;DR: In this paper, a system of calculation for the theory of adsorption in microporous carbon adsorbents for the critical region, i.e., the gaseous state of the adsorbed substance, was developed based on the well-known experimental finding of the linearity of the adorption isosteres.
Abstract: 1.
A system of calculation for the theory of adsorption in microporous carbon adsorbents for the critical region, i.e., the gaseous state of the adsorbed substance, was developed based on the well-known experimental finding of the linearity of the adsorption isosteres.
2.
The isotherms of adsorption of nitrogen by a microporous carbon adsorbent in the 123–293°K temperature and 2–75 kPa pressure regions were studied by a volumetric method.
3.
The adsorption isostere and the standard volatilities based on its parameters for all temperatures studied were calculated with the parameters of the equation for the adsorption isotherm in the theory of volumetric filling of micropores at 123°K and one experimental isotherm at 183°K in the critical region. This permitted calculating the nitrogen adsorption isotherms for the same temperatures. The results of the calculations were in satisfactory agreement with the experimental results.
TL;DR: The optimum conditions for conducting terminal acetylenes with organic halides in the presence of amines, CuI, and palladium complexes were determined in this paper, where the optimal conditions for the coupling reactions of terminal acyclic acid with R'X(Pd, Et3N, PPh3)2 and Pd (II)-R'PdX (PPh3), respectively, were derived.
Abstract: 1.
The optimum conditions for conducting coupling reactions of terminal acetylenes with organic halides in the presence of amines, CuI, and palladium complexes were determined.
2.
Pd(0)-Pd(PPh3)2 and Pd (II)-R'PdX (PPh3)2 complexes are intermediates in the catalytic reactions of RC≡CH with R'X(“Pd,” Et3N, CuI).
TL;DR: The magnitudes and directions of dipole moments of fluoroalkyl groups X(CF2)n, where X=F or H, n=1, 2, and 4, have been determined in this article.
Abstract: 1.
The magnitudes and directions of the dipole moments of fluoroalkyl groups X(CF2)n, where X=F or H, n=1, 2, and 4, have been determined. It has been revealed that there is an increase in the dipole moments of fluoroalkyl groups as the number of F atoms increases up to four and that the terminal H atom has an effect on the dipole moments of a long fluoroalkyl chain.
2.
In the case of a ketone and a complex ester with a HCF2 group, different conformers are stable. This involves eclipsing of the CO group by the Cα-bond in the case of the ketone and eclipsing of the CO bond by the Cα-F bond in the case of the ester.
TL;DR: The HFS constants for the protons in positions 5-13 of the free radical 1,3-diphenyl-1, 4-dihydro- 1,2,4-benzotriazin-4-yl were determined by the DENR method as mentioned in this paper.
Abstract: The HFS constants for the protons in positions 5–13 of the free radical 1,3-diphenyl-1, 4-dihydro-1,2,4-benzotriazin-4-yl were determined by the DENR method.
TL;DR: The main possibility of allyldemetallation of reformatsky reagents has been shown for the first time in the example of the reaction of BrZnCH2CO2Et with CH2=CHCH2Br catalyzed by (λ3-C3H5PdCl)2 and leading to the preparation of CH2-CHCH 2CO2 Et as mentioned in this paper, which is a convenient method for introducing the allyl group into the α-position of esters.
Abstract: 1.
Reactions of organometallic compounds RM (R=Ph, p-MeC6H4, p-BrC6H4, p-MeOC6H4, p-Me2NC6H4, PhCH2, PhCH=CH, 9-fluorenyl, 2-thienyl, PhC≡C; M=MgBr, ZnCl, CdBr, AlCl2) with CH2=CHCH2X (X = Br, OAc, OPh,+NEt3) catalyzedby Pd(PPh3)4 and (λ3-C3H5PdCl)2 in THF have been studied. The influence has been investigated of the nature of metal M, of the organic radical R, and of the leaving group X on the rate of allyl-demetallation and on the yield of products RCH2CH=CH2 and R2.
2.
The reactions of RMgBr (R=Ph, p-MeC6H4, p-BrC6H4, PhCH2, 9-fluorenyl, 2-thienyl) with CH2=CHCH2Br catalyzed by Pd(PPh3)4 proceeded significantly more rapidly and selectively than in the absence of palladium catalyst which made it possible to obtain the corresponding products of allyldemetallation under mild conditions and in high yield.
3.
The main possibility of allyldemetallation of Reformatsky reagents has been shown for the first time in the example of the reaction of BrZnCH2CO2Et with CH2=CHCH2Br catalyzed by (λ3-C3H5PdCl)2 and leading to the preparation of CH2=CHCH2CO2Et. The reaction is a convenient method for introducing the allyl group into theα-position of esters.