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1.
Ghazi A. W. Derwish Salman R. Salman Sabri M. H. Al-Marsoumi 《Journal of inclusion phenomena and macrocyclic chemistry》1994,20(2):123-129
The intermolecular charge transfer (CT) complexes of four crown ethers (CE), viz. B15C5, B18C6, DB18C6 and DB24C8 (as donors), and three acceptors, i.e. tetracyanoethylene (TCNE) 7,7,8,8-tetracyanoquinodimethane (TCNQ) and chloranil were studied in the UV-Visible region in 1,2-dichloroethane (DCE) at 298.2 K. Solid complexes were also prepared and the ratio of the donor to the acceptor was 1:1. Results indicate that the max of the CT band decreases whileK
c (formation equilibrium constant) increases following the systematic change of the electron affinity of the acceptors. TheK
c values suggest that the phenyl group in CE plays a major role in the formation of a CT complex. 相似文献
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V. A. Makarov A. L. Sedov O. S. Anisimova V. G. Granik 《Chemistry of Heterocyclic Compounds》1996,32(6):699-707
Highly polarized enediamines of the a, -diamino--cyano--nitroethylene type have been obtained by the hydrolysis of 4-chloro-5-nitropyrimidines. Several chemical conversions of the enamines obtained have been studied, particularly leading to derivatives of 2-(cyanonitromethylene)imidazoline and -hexahydropyrimidine, and also to derivatives of N, N-bisvinylpiperazine and 7 methylene-1, 4-diazabicyclo(2.2. 1 ]heptane.Center for Drug Chemistry, All-Russian Chemical and Pharmaceutical Research Institute, Moscow 119815. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 811–820, June, 1996. Original article submitted February 6, 1996.For Part 1, see [1]. 相似文献
4.
The reactions of 3-chloropropylphosphonates, 3-chloropropylthiophosphonates, or 3-chloropropylphosphinates with 2-aryloxyethylamines or N-phenylpiperazine afford the corresponding 3-(2-aryloxyethylamino)propylphosphonates and -phosphinates or 3-(4-phenylpiperazin-1-yl)propylphosphonates and -phosphinates. The compounds obtained exhibit -adrenolytic and hypotensive activities, the latter being found to depend on the substituents at the P atom. 相似文献
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A concise synthesis of the isolaurepinnacin skeleton 6 was achieved via the intermolecular allylation of the α-acetoxy ether 3 followed by ring-closing metathesis. This methodology was successfully applied to the convergent synthesis of the oxocene 15, an advanced synthetic intermediate for the total synthesis of laurencin. 相似文献
7.
《Tetrahedron: Asymmetry》1998,9(10):1737-1745
One of the most important features of the synthesis of camphor-derived compounds is the control of the stereochemistry at the C2 position. According to this, reduction of bridgehead-substituted 2-norbornanones 1 and 2-norbornanoximes 3 has been considered by us as a very convenient method for the preparation of different classes of enantiomerically pure 1,2- and 1,3-difunctionalised norbornane derivatives. Factors controlling the stereoselectivity in these reductions, as well as the role played by the nature of the bridgehead functional groups are discussed. 相似文献
8.
The geometries,heats of formation and electronic structures of 15 azido-derivatives of 1,2,3-TNB (Ⅰ),1,2,4-TNB (Ⅱ) and 1,3,5-TNB (Ⅲ) have been studied using quantum chemical AMI method at HF level.The effect of azido substitution on the structures and properties of TNBs has been discussed and the relative stability of the title compounds has been established.The processes of the decomposition of the title compounds by breaking C-NO2,C-N3 and CN-N2 bonds are investigated at UHF-AM1 level.It is shown that the decomposition of the title compounds may be initiated by the cleavage of both C-NO2 and N-N2 bonds. 相似文献
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A. Baranski 《Chemistry of Heterocyclic Compounds》2000,36(6):738-743
It is shown using spectroscopic methods that the [2+3]-cycloaddition of Z-C-phenyl-N-arylnitrones to E--nitrostyrene is regiospecific and leads to a mixture of the corresponding (3SR,4SR,5SR)- and (3SR,4SR,5SR)-2-aryl-4-nitro-3,5-diphenylisoxazolidines. The regioselectivity of the reaction is explained in terms of hard and soft acid and base theory.For communication 44, see [1]Institute of Organic Chemistry and Technology, T. Kosciuszko Krakow Polytechnic, 31–155 Krakow. Poland: e-mail: pebarans(ausk.pk.edu.pl. Translated from Khimiya Geterotsiklicheskikh Soedinenii No. 6. pp. 840–846, June, 2000. 相似文献
11.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1989,45(2):299-304
The i.r. and Raman spectra of the heptahydroborate ion, [B2H7]−, and its deuterated derivative, [B2D7]−, have been obtained in solution and assignments have been made of the observed bands. The data are interpreted as indicating a bent C2 structure in solution. Normal coordinate calculations based on this model are presented. 相似文献
12.
Roba Moumné 《Tetrahedron letters》2008,49(32):4704-4707
We describe here the aminomethylation of chiral silyl enol ether derivatives using iminium ion. The choice of judicious precursors with adequate protecting groups for the silylation/aminomethylation step was required to achieve the synthesis of β2-homotryptophane in few steps. The same methodology was used to prepare a β2-homolysine derivative. 相似文献
13.
B. T. Ibragimov K. M. Beketov S. A. Talipov W. L. Duax P. Strong 《Chemistry of Natural Compounds》1995,31(5):570-574
The structure of the product of condensation of gossypol with (–)--phenylethylamine has been determined. It has been shown that a possible cause of the difficulty in separating racemic gossypol into optically active components is not a racemization of (–)--phenylethylamine on its condensation with gossypol but the high tendency of gossypol and its derivatives to form dimers.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 676–681, September–October, 1995. Original article submitted February 6, 1995. 相似文献
14.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1983,39(2):127-136
The i.r. and Raman spectra of the dimethylhalosilanes, Me2SiHZ and Me2SiDX (X = F, Cl, Br, I) have been recorded and the fundamental vibrations assigned. Analysis of the spectra of the deuterated compounds indicate that existing assignments for Me2SiHX are in error. 相似文献
15.
Studies on the mechanism and intermediate products in the Friedel–Crafts reaction between oxetanols and phenols are presented. The formation of O-alkylated intermediates is identified using 1H NMR spectroscopy, in a reversible formation of the kinetic oxetane ether products. An interesting relationship between the electronic nature of the nucleophile and the degree of O-alkylation is uncovered. For phenols substituted with an electron withdrawing group such as CN, oxetane ethers are the only products isolated regardless of reaction time. Increasing the electron rich nature of the phenol leads to an increased proportion of the thermodynamic C-alkylated Friedel–Crafts products after just 1?h and as the sole product/s after extended reaction times. These studies have enabled a more complete catalytic cycle to be proposed. Using the same lithium catalyst and carefully selected reaction times, several examples of oxetane ethers are successfully isolated as novel bioisosteres for ester groups. 相似文献
16.
Qizhong Zhou Liangjun Su Haining Gu Tiansheng Jiang Fangli Qiu Yuyuan Ye Huajiang Jiang Deman Han Guoliang Dai Shibin Ren Rener Chen 《Tetrahedron letters》2014
Host–guest complexation between two 1,5-dinaphtho-crown ethers and two paraquat derivatives has been studied. By self-assembly of 1,5-dinaphtho-44-crown-12 (DNP44C12) 1 with vinylogous viologen 4, a linear [2]pseudorotaxane array forms in the solid state by PF6− anion linkages. Moreover, the complexation between 1,5-dinaphtho-50-crown-14 (DNP50C14) 2 and paraquat 3 also leads to the formation of a linear [2]pseudorotaxane superstructure in the solid state driven by π–π stacking. 相似文献
17.
R. A. Karakhanov V. I. Kelarev A. S. Remizov Yu. N. Polivin D. Oietaio 《Chemistry of Heterocyclic Compounds》1992,28(10):1112-1115
The condensation of N-furfuryl- and N-tetrahydrofurfurylethylenediamines with hydrochloride salts of iminoesters of carboxylic acids gives 1,2-disubstituted 2-imidazolines containing furfuryl or tetrahydrofurfuryl groups at N1.For communication 2, see [1]Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1312–1315, October, 1992. 相似文献
18.
The product from the reduction of ethyl spiro-3,3-(ethylenedioxy)-2-oxindole carboxylates (1) using borohydride salts has been found to be dependant upon both solvent and metal ion. With polar solvents and lithium bromide/sodium borohydride, spiro-3,3-(ethylenedioxy)-2-hydroxyindole carboxylates (2) are obtained in high yields whilst [2-(2-hydroxymethyl-[1,3]dioxolan-2-yl)-phenyl]-carbamic acid ethyl esters (3) are obtained using sodium borohydride in less polar solvents. 相似文献
19.
3-(Pyrazol-5'-yl)coumarin (3) was prepared from condensation of 3-(2'-formyl-1'-chlorovinyl)-coumarin (1) with hydrazine hydrate at room temperature, followed by cyclization with base. Salicylaldazine was prepared from methoxylation of 1 to give acetal 7, followed by condensation of 7 with hydrazine hydrate at 80℃. Treatment of acetal 7 with thiourea yielded the corresponding 4-substituted-2-thioxo-2H-pyrimidine [ 3, 4-b]-coumarin (12). 相似文献
20.
A method for the synthesis of glycoclusters by N-alkylation of N-glycyl-β-lactosylamine with N-chloroacetyl derivatives of β-lactosylamine and N,N’-iminodiacetyldilactosylamine has been developed. The glycoclusters obtained with two and three lactosylamine residues with
the amino group in the spacer were found to be suitable for further conjugation with carboxy-containing physiologically active
compounds.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 647–651, March, 2008. 相似文献