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1.
S. G. Dzhavakhishvili A. V. Borisov V. M. Nikitchenko S. N. Kovalenko 《Chemistry of Heterocyclic Compounds》2007,43(1):98-105
The cyclization of unsymmetrical 2-mercaptoimidazoles with aliphatic and aromatic ketones has been studied. Using 1H NMR and X-ray analysis it has been shown that 4-R1-1H-2-mercaptoimidazoles undergo selective oxidative cyclization to the corresponding 3-R3-2-R2-6-R1-imidazo[2,1-b][1,3]thiazoles while 6-R4-1H-2-mercaptobenzo[d]imidazoles give a mixture of 6-R4-3-R2-2-R3-benzo[4,5]imidazo[2,1-b][1,3]thiazole and 7-R4-3-R2-2-R3-benzo[4,5]imidazo[2,1-b][1,3]thiazole in the ratio 1: 1.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 115–122, January, 2007. 相似文献
2.
We report the results of a semiempirical PM3 study of the 1,4 cycloaddition reaction of substituted λ3-phosphabenzenes with alkynes. The influence of the nature, position and steric hindrance of substituents on the reaction
energy is studied. Except for some values, the results are in reasonable agreement with experimental observations and electronic
effects of substituents. 相似文献
3.
The reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2λ3-phospholidine withC,N-diphenylnitrilimine is a multistage process, in the course of which the 1,2,4-diazaphosphorine ring is formed and both rings
of the initial organophosphorus compound are cleaved. 5-(2-Chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,3-diphenyl-1,4-dihydro-1, 2,4λ5-diazaphosphorine was obtained as the final product.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–128, January, 2000. 相似文献
4.
The reaction of 2-(4,5-dihydrofur-3-yl)-1,3-diphenyl-1,3-diaza-2λ3-phospholidine withC,N-diphenylnitrilimine is a multistage process, in the course of which the 1,2,4-diazaphosphorine ring is formed and both rings
of the initial organophosphorus compound are cleaved. 5-(2-Chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,3-diphenyl-1,4-dihydro-1, 2,4λ5-diazaphosphorine was obtained as the final product.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–128, January, 2000. 相似文献
5.
Condensation of levoglucosenone with the carbanion ofrac-allyl phenyl sulfoxide, in contrast with reactions of this anion with the majority of other unsaturated ketones, proceeds
without regio- or enantioselectivity to give a (1.0–1.8): 1 mixture of products of both 1,2- and 1,4-γ-addition of the allylic
residue. Each product is a (1.2–1.6): 1 mixture of epimers at the asymmetric sulfur atom.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 157–159, January, 1999. 相似文献
6.
Reactions of 2-(4,5-dihydro-3-furyl)-1,3-diphenyl-1,3-diaza-2λ3-phospholidine (1) with nitrile imines are multistep processes involving cleavage of one P-N bond of the diazaphospholidine ring to form substituted
5-(2-chloroethyl)-4-(N,N′-diphenylethylenediamino)-1,4-dihydro-1,2,4λ5-diazaphosphorines 4 as final products. Analogs of phospholidine 1, namely, 4,5-dihydro-3-furylphosphonous dipiperidide and dimorpholide, react with C,N-diphenylnitrile imine with retention of both P-N bonds to give 5-(2-hydroxyethyl)-1,2,4-diazaphosphorinium chlorides.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1590–1593, July, 2005. 相似文献
7.
Hyun-Jung Lee Oh-Kyu Lee Yeong-Han Kwon Don-Ha Choi Ha-Young Kang Hyeon-Yong Lee Ki-Hyon Paik Hak-Ju Lee 《Chemistry of Natural Compounds》2006,42(4):415-418
Four known isoflavone glucosides have been isolated from the bark of Amorpha fruticosa, which is a traditional remedy plant,
for the first time. They were elucidated as 3′-hydroxy-4′-methoxyisoflavone-7-O-β-D-glucopyranoside (1), 4′,6-dimethoxyisoflavone-7-O-β-D-glucopyranoside (2), 4′-methoxyisoflavone-7-O-β-D-glucopyranoside (3), and 3′,5-dihydroxy-4′-methoxyisoflavone-7-O-β-D-glucopyranoside (4), based on the UV, FT-IR, EIMS, FABMS, HREIMS, and NMR (1H and 13C, DEPT, COSY, NOESY, HMQC, and HMBC) data.
Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 336–338, July–August, 2006. 相似文献
8.
V. Ya. Sosnovskish S. Foro H. J. Lindner I. I. Vorontsov Yu. A. Azev 《Russian Chemical Bulletin》2000,49(11):1910-1913
It was demonstrated by X-ray diffraction analysis that the reaction of 3,3-dimethyl-6-trifluoromethyl-2,3-dihydro-4-pyrone
with hydroxylamine afforded 5-hydroxyamino-3-(2-hydroxy-1,1-dimethylethyl)-5-trifluoromethyl-Δ2-isoxaline.
Published inIzvestiya Akademic Nauk. Seriya Khimicheskaya. No. 11, pp. 1941–1944, November, 2000. 相似文献
9.
We have studied isomerization of 6-substituted 5-hydroxy-3-propargylthio-1,2,4-triazines using base catalysis. We have used
NMR correlation spectroscopy (1H/15N HMBC spectra) to prove the structure of the regioisomer formed. The type of regioisomer formed (3,6-dimethylthiazolo[3,2-b]-1,2,4-triazin-7-one)
allows us to say that isomerization occurs as a direct propynyl rearrangement.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 453–457, March, 2006. 相似文献
10.
11.
Mirgorodskaya A. B. Kudryavtseva L. A. Zuev Yu. F. Idiyatullin B. Z. Fedotov V. D. 《Russian Chemical Bulletin》2001,50(2):245-249
High-resolution 1H NMR technique with Fourier-transform and pulsed-gradient spin-echo was used to study the structure of oil-in-water microemulsions based on cetylpyridinium bromide. The sizes of microdrops and the distribution of components between the disperse and continuous phases were found. It was shown for the hydrolytic decomposition of O,O-bis-(p-nitrophenyl) methyl phosphonate in the presence of amines that the microemulsion medium can affect both the rate and mechanism of hydrolysis. The reaction rate constants depend on the structure of microdrops. 相似文献
12.
O. B. Flekhter L. A. Baltina L. V. Spirikhin I. P. Baikova G. A. Tolstikov 《Russian Chemical Bulletin》1998,47(3):513-516
Betulin 2-deoxy-α-d-, 2-deoxy-α-l-, and 2,6-dideoxy-α-l-arabino-hexopyranosides were synthesized by acid-catalyzed glycosylation (cationite in the H+ form, LiBr) of betulin 3- and 28-monoacetates with glycal acetates.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 531–534, March, 1998. 相似文献
13.
A. Yu. Lepeshkin K. F. Turchin E. G. Gal’pern I. V. Stankevich K. A. Lyssenko V. S. Velezheva 《Russian Chemical Bulletin》2007,56(7):1447-1455
Based on the results of studies of the deuterium exchange and dehydration of 4-hydroxy-Δ2-thiazolines and 2-R-4-acetyl-8b-hydroxy-3a,8b-dihydro-4H-thiazolo[5,4-b]indoles containing the α-methylene (methine) unit at the C(2) atom, the mechanism of dehydration of these compounds generated
as intermediates in the Hantzsch synthesis of thiazoles and 2-R-4-acetyl-4H-thiazolo[5,4-b]indoles was proposed. This mechanism includes an additional step of the formation of the corresponding Δ3-thiazolines. According to the results of quantum chemical calculations, this is energetically more favorable than the dehydration
in terms of the commonly accepted mechanism. In some cases, an acidic medium impedes the dehydration of 4-hydroxy-Δ2-thiazolines or their cyclic analogs. The proposed mechanism provides an explanation for the empirical data on the differences
in the reactivities of both thioamides and α-haloketones, which have remained unexplained in terms of the commonly accepted
mechanism. The spontaneous thiazole synthesis is virtually impossible starting from thioamides of aromatic or heteroaromatic
acids and α-haloketones bearing electron-withdrawing α′ substituents or cyclic bromoindoxyl-type haloketones. In the thiazole
synthesis from these starting components, it is expedient to perform dehydration under basic catalysis.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1394–1402, July, 2007. 相似文献
14.
G. R. Dey 《Research on Chemical Intermediates》2007,33(7):599-611
Gamma radiolysis of oxygenated 1–10 mM azide solutions was carried out at various pH values. In oxygenated 10 mM azide solutions,
H2O2 and NO
2
−
were observed as radiolytic products while NH3 was not. The concentration of H2O2 reached its maximum level at a dose of 1 kGy, whereas NO
2
−
yield increased non-linearly beyond 2 kGy in this system. Both in aerated and oxygenated systems, G(NO
2
−
) and G(H2O2) were found to vary with N
3
−
concentration. The yield of NO
2
−
was found to be dependent on both dose rate and pH. On pulse radiolysis, NO
2
−
was found as a radiolytic product in aerated 1 mM azide solution at pH 6.8. In this system the intermediate generated exhibits
absorbance around 250 nm. The overall results obtained during the present study reveal that in presence of both reducing radical
(mainly e
aq
−
) and oxygen, N
3
−
produced an intermediate possibly NH2O
2
•
radical, which is the prime source for NO
2
−
generation. 相似文献
15.
S. E. Malykhin V. F. Anufrienko E. J. M. Hansen E. V. Kuznetsova T. V. Larina G. M. Zhidomirov 《Journal of Structural Chemistry》2007,48(5):855-861
A simple qualitative method to analyze d-d-electronic transitions in cations of the transition elements in oxide matrices is proposed. In the particular case, all the excited states of interest differ only in the electronic configuration of d-orbitals, and the energies of transitions can be computed via the configuration interaction (CI) method restricted by the active space of five cation d-orbitals. An ordinary cluster model that takes into account the first coordination sphere of transition metal ion consisting of the framework of oxygen ions is sufficient for this purpose. The systematic overestimation error of transition energies can be corrected through the empirical factor calculated to fit experimental UV-VIS spectra. The physical meaning of the scaling factor proposed is the dynamic part of electron correlation that remains unaccounted for in the chosen active CI space. The observed d-d-transitions of Fe3+ ions in MFI zeolites are analyzed in detail. It is suggested that the specifics of the observed electronic spectra are caused by the distortion of the tetrahedron of oxygen atoms around Fe3+. The latter can be easily taken into account when selecting an appropriate Fe3+ cluster model in the framework. It is shown that the occurrence of the weak low-frequency band below 21,000 cm?1 indicates the distortion of the tetrahedral environment around Fe3+. 相似文献
16.
The reaction of hexafluoro-cyclo-triphosphazene P3N3F6 with ammonia in acetonitrile has been studied. New compounds, (2-imino-2,4,4,6,6-pentafluoro-2λ5,4λ5,6λ5-cyclo-triphosphaza-1,3,5-trienyl)-2-amino-4,4,6,6-tetrafluoro-2λ5,4λ5,6λ5-cyclo-triphosphaza-1,3,5-triene, P3N3F5–NH–P3N3F4NH2 (2) and cis and trans isomers of non-gem-2,4-diamino-2,4,6,6-tetrafluoro-2λ5,4λ5,6λ5-cyclo-triphosphaza-1,3,5-triene, P3N3F4(NH2)2 (4, 5), were detected by GC/MS, and 31P NMR spectroscopy in reaction mixtures. X-ray diffraction analysis of P3N3F5–NH–P3N3F4NH2 (2) revealed two conformational polymorphs, 2A and 2B, the latter being built up of two different conformers that were further denoted as 2Ba (the same as the single conformer in 2A) and 2Bb. The compound 2 was characterized by spectroscopic methods and its 2D potential energy surface (PES) was described by density functional theory computations depending on two dihedral angles. The calculated PES spans over 30 kJ/mol in energy including 8 local minima and all first and second order saddle points. The occurrence of the two experimentally observed conformers 2Ba and 2Bb seems to be governed by crystal packing effects. 相似文献
17.
(R)-4-Menthenone in the synthesis of optically pure sex pheromone of the peach leafminer moth (Lyonetia clerkella) 总被引:1,自引:0,他引:1
Kharisov R. Ya. Latypova E. R. Talipov R. F. Muslukhov R. R. Ishmuratov G. Yu. Tolstikov G. A. 《Russian Chemical Bulletin》2003,52(10):2267-2269
The synthesis of (14S)-methyloctadec-1-ene, sex pheromone of the peach leafminer moth (Lyonetia clerkella), is described to demonstrate a new potential of the synthetic use of (R)-4-menthenone. 相似文献
18.
S. M. Ramsh A. G. Ivanenko N. L. Medvedskiy D. G. Lagerev D. B. Lazarev L. N. Belobrzeckaja Costa 《Chemistry of Heterocyclic Compounds》2006,42(8):1086-1093
It was found that the aminomethylation of 2-amino-5,5-bis(hydroxymethyl)-1,3-thiazol-4(5H)-one and its spiro analogs using
primary amines is accompanied by cyclization at the amidine fragment of the molecule with annelation of a tetrahydrotriazine
ring. When using secondary amines the aminomethylation occurs at the exocyclic nitrogen atom.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1252–1260, August, 2006. 相似文献
19.
E. O. Chukhadzhyan A. R. Gevorkyan A. A. Khachatryan El. O. Chukhadzhyan G. A. Panosyan 《Chemistry of Heterocyclic Compounds》2006,42(9):1151-1157
p-Bis{3-[N,N-dialkyl-N-(4-hydroxybut-2-ynyl)ammonio]prop-2-ynyl}benzene dichloride in the presence of catalytic amounts of
aqueous alkali is subject to a double intramolecular cyclization forming benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium
dichloride in 40–42% yield. Simultaneously an intramolecular recyclization takes place with the formation of dialkyl(6-dialkylaminomethyl-7,9,10,12-tetrahydro-8,11-dioxadicyclopenta[c,g]phenanthren-1-ylmethyl)amines
in 7–9% yield. The same compounds are obtained in 70–72% yield by the recyclization of benzo[5,6;5′,6′-a,c]di(2,2-dialkyl-4-hydroxymethyl)isoindolinium
dichlorides under conditions of aqueous alkaline degradation.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1329–1335, September, 2006. 相似文献
20.
P. I. Abronina L. V. Backinowsky A. A. Grachev S. L. Sedinkin N. N. Malysheva 《Russian Chemical Bulletin》2005,54(5):1287-1293
Methyl 2,4-di-O-benzoyl-α-D-mannopyranoside was used as a key intermediate in the synthesis of 3,6-branched mannopentaoside bearing one terminal D-[1-13C]mannopyranose residue, viz., methyl 6-O-[3,6-di-O-(α-D-mannopyranosyl)-α-D-mannopyranosyl)-3-O-{α -D-[1-13C]mannopyranosyl}-α-D-mannopyranoside.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
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Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1250–1255, May, 2005. 相似文献