首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Abstract  A simple and efficient catalytic oxidation of urazoles and a bis-urazole to the corresponding triazolinediones by treatment with Al(NO3)3.9H2O in the presence of a catalytic amount of silica sulfuric acid is described. A good range of urazole derivatives was selectively oxidized in CH2Cl2 at room temperature in good to excellent yields. Graphical abstract     相似文献   

2.
Abstract  A simple, highly efficient, and green protocol has been developed for preparation of sulfides from alkyl or aryl thiols and benzyl-, allyl-, t-butyl, and adamantyl halides under solvent- and catalyst-free conditions. Graphical abstract     相似文献   

3.
Abstract  An efficient and direct procedure for the synthesis of novel spiro[isoindoline-1,2′-quinazoline]-3,4′(3′H)-dione derivatives is described. The process employs a condensation reaction of 2-aminobenzamides and isatins in the presence of a catalytic amount of KAl(SO4)2.12H2O (alum) in ethanol under reflux. Graphical Abstract     相似文献   

4.
Abstract  The reaction between dibenzoylacetylene and enol systems, such as acetylaceton or cyclohexane-1,3-dione in the presence of triphenylphosphine in THF/H2O, leads to 4-acetyl-3-benzoyl-1-phenyl-1,5-hexanedione and 2-hydroxy-3-(2-oxo-2-phenylethyl)-2-phenyl-3,5,6,7-tetrahydro-1-benzofuran-4(2H)-one. Subsequently, these compounds undergo cyclization and elemination reactions in acidic dichloromethane at room temperature to produce known highly functionalized furan derivatives. Graphical abstract     相似文献   

5.
Abstract  One-pot, three-components synthesis of 2,4,6-triarylpyridines and 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones was performed under solvent-free conditions using molecular iodine as the catalyst in moderate to good product yields. Graphical abstract     相似文献   

6.
Abstract  New C-furyl glycosides bearing pyrazolines, isoxazolines, and dihydropyrimidine-2(1H)-thiones were synthesized in order to increase the number of tested compounds screened for antimicrobial activity. The antimicrobial activity screening showed that the pyrazoline derivatives were the most active compounds. Graphical abstract     相似文献   

7.
Abstract  In contrast to the results presented in a previous report, the direct conversion of alcohols to alkyl fluorides with triphenylphosphine and potassium fluoride in CCl4/DMF under mild conditions failed. Graphical Abstract     相似文献   

8.
Abstract  A 3D metal-organic framework, [C6H3CdN2O4]·NH4, was synthesized solvothermally and structurally characterized by single-crystal X-ray structure determination. This compound crystallizes in the tetragonal system with the space group P42/nmc. The crystal structure presents a 3D framework and open channels, exhibiting guest-coordination sites at channel walls and strong fluorescent emission. Graphical abstract     相似文献   

9.
Abstract  (+)-Lortalamine was synthesised using (S)-(−)-α-methylbenzylamine as a chiral auxiliary. The stereochemistry of an intermediate compound was established on the basis of X-ray crystallography, allowing unambiguous assignment of the absolute configuration. Graphical abstract     相似文献   

10.
Abstract  (Z)-3-(3,4-diaryl-1,2,4-triazole-5-yl)prop-2-enoic acid derivatives were obtained in the course of the reaction of N 3-substituted amidrazones with maleic anhydride, and isomerized into the (E) isomers by heating under reflux in acetic acid solution. The molecular structure of the compounds obtained was confirmed by IR and 1H NMR spectroscopy, and by X-ray crystallography for (2E)-3-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)prop-2-enoic acid. The antiviral and immunomodulating activity of several of the compounds was examined. Graphical abstract     相似文献   

11.
Abstract  The stability constant of the dibenzo-18-crown-6·H3O+ cationic complex species dissolved in nitrobenzene saturated with water has been determined from extraction experiments in the two-phase water–nitrobenzene system and from γ-activity measurements. Various structures of protonated dibenzo-18-crown-6 are discussed. Graphical abstract     相似文献   

12.
Abstract  Chloroperoxidase from Caldariomyces fumago catalyses oxidation of indole and thioanisole in reaction mixtures containing up to 40% (v/v) of different ionic liquids (ILs). Results indicate that ILs containing tosylate, trifluoroacetate, chloride, and methylsulfate anions are suitable cosolvents for these transformations, yielding high enantiomeric excess and good conversion rates. Graphical abstract    相似文献   

13.
Abstract  From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constant of protonated tetraethyl p-tert-butylcalix[4]arene tetraacetate in nitrobenzene saturated with water was determined. By using DFT calculations, the most probable structure of the tetraethyl p-tert-butylcalix[4]arene tetraacetate·H3O+ complex species was derived. Graphical Abstract     相似文献   

14.
Abstract  Bis[N-(1-pyrenylmethyl)salicylideneaminato]zinc(II) emits intense fluorescence on excitation of the pyrenyl group. This fluorescence originates from the excited state of the salicylideneamine moiety, indicating that efficient intramolecular energy transfer takes place. The occurrence of such efficient energy transfer is accounted for by significant spectral overlap between the emission from the S1 state of the pyrenyl group and the absorption of the salicylideneamine–zinc complex. Graphical abstract     相似文献   

15.
Abstract  Molecular iodine generated in situ from Fe(NO3)3·9H2O/NaI acts as a highly efficient catalyst for tetrahydropyranylation of various alcohols and phenols with 3,4-dihydro-2H-pyran in almost quantitative yields. The reaction occurs rapidly in dichloromethane at room temperature, and use of toxic molecular iodine is avoided. Graphical Abstract     相似文献   

16.
Abstract  Stable paramagnetic Cr(II) and Cr(III) bis(alkynyl) complexes of the type [trans(RC≡C)2Cr(dmpe)2] n+ (R = Ph, SiMe3, SiEt3, C≡C–SiMe3 n = 0, 1) were prepared and characterised by NMR, cyclic voltammetry, EPR, magnetic measurements, and X-ray single-crystal diffraction studies. Graphical Abstract     相似文献   

17.
Abstract  A new route to the synthesis of 2-arylthieno[2,3-d]pyrimidin-4(3H)-ones has been developed through heterocyclization of 2-amino-4,5-dimethylthiophene-3-carboxamide with aromatic aldehydes in boiling glacial acetic acid followed by air oxidation. The unoxidized intermediates, 2-aryl-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones, are isolated when the reactions are carried out either at room temperature or under a nitrogen atmosphere. Graphical Abstract     相似文献   

18.
Abstract  A novel method for the synthesis of 3-(2-substituted ethyl)-2-methylbenzohetero[3,2-a]pyrimidines in high yield (80–85%) was achieved, which involves a dihydrofuranone intermediate, readily obtained from β-ketolactone to 2-aminobenzoheterocycles. The major advantage of the methodology is the high yield and product purity. Graphical Abstract     相似文献   

19.
Abstract  Electro-oxidation of catechol in the presence of 2-methyl-1,3-cyclopentanedione as a nucleophile was investigated in water–acetonitrile (90:10 v/v) solution. The results indicate that the o-benzoquinone electrogenerated participates in a Michael addition reaction with this nucleophile. The electrosynthesis of 2-(3,4-dihydroxyphenyl)-2-methylcyclopentane-1,3-dione was carried out. The product was characterized by NMR, MS, FT-IR, and elemental analysis. An EC mechanism was deduced from voltammetric and spectroscopic data. Also, the Michael addition reaction rate constant (k m) was estimated using digital simulation of voltammograms. Graphical abstract   Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

20.
Abstract  A simple method for the straightforward regioselective synthesis of 2,3-mannoepoxy-β-cyclodextrin, which is a valuable precursor for further functionalization of β-cyclodextrin, is achieved under aqueous conditions without any organic solvents at a moderate yield. Graphical abstract     相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号