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1.
Microwave was found to catalyze stereoselective conversion of dialkyl 2-(imido-N-yl)-3-(triphenylphosphoranylidene)butanedioates to electron-poor (Z)-N-vinylimides in the presence of iron(II) sulfate powder in solvent-free conditions in 4 min.  相似文献   

2.
Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by phenols (1-hydroxynaphthalene, 2-hydroxynaphthalene, 4-bromophenol, 2-hydroxybenzaldehyde, and 5-bromo-2-hydroxyben- zaldehyde) leads to vinyltriphenylphosphonium salts, which undergo electrophilic substitution reaction with conjugate base to produce corresponding stabilized phosphorus ylides. Microwave was found to catalyze conversion of the stabilized phosphorus ylides to chromene derivatives in the presence of solid catalysts in solvent-free conditions at microwave power 0.4 KW in 3 min.  相似文献   

3.
Manganese dioxide was found to catalyze stereoselective conversion of dialkyl 2-(imido-N-yl)-3-(triphenylphosphoranylidene)butanedioates to electron-poor (Z)-N-vinylimides in solvent-free conditions at 95°C in high coversions.  相似文献   

4.
Abstract

Potassium dihydrogen phosphate powder and sodium dihydrogen phosphate powder were found to catalyze stereoselective conversion of dialkyl 2-(imido-N-yl)- 3-(triphenylphosphoranylidene)butanedioates to electron-poor (Z)-N-vinylimides in solvent-free conditions under microwave irradiation in 5-6 minutes in high conversions.  相似文献   

5.
Silica gel was found to catalyze the stereoselective conversion of dialkyl 2-(imido- N -yl)-3-(triphenylphosphoranylidene)butanedioates to electron-poor ( Z )- N -vinylimides in solvent-free conditions at 95°;C in high coversions.  相似文献   

6.
Tetrabutylammonium hydrogen sulfate (TBAHS) as[3pc] a solid protic acid and phase-transfer reagent catalyzed the three-component condensation reactions of aldehydes, 1,3-dicarbonyl compounds, and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80°C.  相似文献   

7.
标题化合物C11H10O4的晶体结构用X-射线单晶衍射法测定。晶体属单斜晶系, P21/c空间群, 晶胞参数a = 12.136(1), b = 5.559(1), c = 14.615(2) ? b = 96.758(3), V = 979.1(3) ?, Z = 4, Mr = 206.19, Dc = 1.399 g/cm3, F(000) = 432, m(MoKa) = 0.107 mm-1。晶体结构用直接法解出, 经全矩阵最小二乘法对原子参数进行修正, 最终的偏离因子为R = 0.0453, wR = 0.0990。标题化合物形成了1个大的共轭体系, 含有1个稳定的烯醇结构。结构测定表明还存在着1个分子内氢键的结构, 它使烯醇结构更加稳定。  相似文献   

8.
构建了羰基还原酶CR2重组酶体系,并优化了相关的酶促催化反应条件.通过在催化体系中添加辅酶NADP+(0.1 mmol/L)和辅底物葡萄糖(120 g/L),在30℃及p H=8.0的条件下反应4 h,CR2重组酶体系不对称还原N,N-二甲基-3-酮-3-(2-噻吩)-1-丙胺(DKTP,10 g/L),合成了高光学纯度(S)-N,N-二甲基-3-羟基-3-(2-噻吩)-1-丙胺[(S)-DHTP,e.e.值99.9%],产率为62%.在酶促催化过程中,由于辅酶循环生成葡萄糖酸导致反应体系p H值下降而影响催化效率.通过调控反应体系p H值,(S)-DHTP的产率提高到68%.不同浓度底物的反应过程表明底物对CR2酶促反应具有抑制作用,且在10 g/L底物浓度下反应的时空产率可达1.3 g·L-1·h-1.  相似文献   

9.
The title compound,(Z)-methyl-3-methoxy-2-{2-[(4-(E-3-p-tolylacryloyl)phenoxy)-methyl]phenyl}acrylate,was synthesized and determined by X-ray single-crystal diffraction. The crystal belongs to the triclinic system,space group P1 with a = 8.0157(8),b = 12.5748(13),c = 13.3768(14) ,α = 64.770(2),β = 75.720 (2),γ = 89.784(2)°,μ = 0.085 mm-1,Mr = 442.49,V = 1174.1(2) 3,Z = 2,Dc = 1.252 g/cm3,F(000) = 468,T = 294(2) K,R = 0.0603 and wR = 0.1498 for 2644 observed reflections with I 2σ(I). X-ray diffraction analysis reveals that the single crystal contains strong non-classical hydrogen bonds. The preliminary bioassay showed that the title compound exhibits inhibitory activity against the Pseudoperoniospora cubensis and Rhizoctonia solani at the test concentration of 200 mg/L.  相似文献   

10.
Oxidation of 2-hydroxy-3-nitrochalcones with thallium(III) nitrate gives (Z)-2-phenylmethylene-7-nitrobenzofuran-3(2H)-one derivatives, rather than the more usual 1,2-diaryl-3,3-dimethoxypropan-1-ones or the corresponding isoflavones.
Oxydative Cyclisierung von Chalconen mit Thallium(III)nitrat: Synthese von (Z)-2-Phenylmethylen-7-nitro-3(2H)-benzofuranonen (Kurze Mitteilung)
Zusammenfassung Die Oxidation von 2-Hydroxy-3-nitrochalconen mit Thallium(III)nitrat ergab (Z)-2-Phenylmethylen-7-nitro-3(2H)-benzofuranon-Derivate und nicht die üblichen 1,2-Diaryl-3,3-dimethoxypropan-1-one bzw. die entsprechenden Isoflavone.
  相似文献   

11.
1 INTRODUCTION In contrast to the old-line academic and practical studies of 1-phenyl-3-methyl-4-benzoyl-5-pyrazo- lone (PMBP) on the metal coordination chemistry[1], the complexes of β-ketoamines derivated from PMBP received little attention due to its complicated com- plexation. However, in recent years, there has a sudden growth of this area as a result of its timely interest in biological activities[2]. Recently, a series of β-ketoamines[3] containing PMBP have been prepared fro…  相似文献   

12.
N,N-Dialkylhydrazides of S-(4,6,7-trichloro-2,5-dihydroxy-2,3-dihydrobenzo[b]-3-furanyl)dithiocarbonic acids have been obtained by the reaction of 3,4,6,7-tetrachloro-2,5-dihydroxy-2,3-dihydrobenzo[b]furan with N,N-dialkylhydrazinium salts of N,N-dialkylhydrazides of dithiocarbonic acids. Recyclization in boiling ethanol in the presence of conc. HCl with subsequent oxidation leads to the formation of 3-N,N-dialkylamino-5-(3,5,6-trichloro-1,4-benzoquinon-2-yl)thiazoline-2-thiones. An attempt at recyclization in boiling trifluoroacetic acid led to the formation of 3-N,N-dialkylamino-5,6,8-trichloro-7-hydroxy-2,3,3a,8b-tetrahydrothiazolo[4,5-b]benzo[d]furane-2-thiones.  相似文献   

13.
A variety of aliphatic, aromatic, and heteroaromatic thiols were rapidly and cleanly converted to their corresponding disulfides in excellent yields using n-butyltriphenylphosphonium dichromate (BTPPDC) in acetonitrile solution under solvent-free conditions and microwave irradiation. Selective oxidation of thiols in the presence of other oxidizable functional groups, such as alcohol and sulfide, is a noteworthy advantage of this method.  相似文献   

14.
3—甲氧基—甲亚胺H光度法测定植物中硼的研究及应用   总被引:8,自引:1,他引:7  
研究了3-甲氧基-甲亚胺H与硼的显色反应。在乙酸-乙酸铵缓冲溶液中。硼与3-甲氧基-甲亚胺H形成1:2的黄色配合物,最大吸收在420nm波长处,摩尔吸尤系数为7.19×10~3,Sandell灵敏度为0.0015/μg·cm~(-2)。当硼含量在0~35μg/25ml范围内符合比耳定律,应用于植物中硼的测定获得满意的结果。  相似文献   

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