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1.
前言核苷三磷酸是含有两个高能磷酸键的高能化合物。除了参与核糖核酸合成外,在生物体内的生命活动中起着重要的作用。ATP 主要用于供给合成细胞的物质所需要的能量,也是被称为“第二信使”的环化AMP(3′5′-cyclicAMP)的前体。而后者已知与多种生化过程有关。CTP 参与重要磷脂类的合成。GTP 在蛋白质合成中是必不可少的。UTP 是肝脏中重要解毒剂尿二磷葡萄糖醛酸(UDPG)的前体,与肝糖元、酸性粘多糖的合成密切相关。根据已知的生理功能有些兄弟研究单位作了一些临床应用试验,还值得进一步探讨。  相似文献   

2.
Complexes of 2,2-bipyridine-6,6-bis(carbothioamide), obtained with a variety of metal cations, were characterised by microanalyses, molar conductivities and by i.r. and n.m.r. (for diamagnetic compounds) spectra. The iron(II) complex was also characterised by Mössbauer spectroscopy. The spectral data indicate that, in all cases, the ligand coordinates to the metal through one pyridine nitrogen and one sulphur.  相似文献   

3.
4.
A facile procedure for the synthesis of 3-(2′-amino-3′-cyano-4′-arylpyrid-6′-yl)coumarins are being reported starting from 3- acetylcoumarin,aromatic aldehydes and malononitrile.The reactions were carded out on microwave irradiation in good yield with short time and easy work-up.The structures of all the compounds have been confirmed on the basis of their analytical,IR,~1H NMR, and mass spectral data.  相似文献   

5.
《Tetrahedron: Asymmetry》2000,11(9):1919-1925
The synthesis of (R)- and (S)-7,7′-dimethoxy-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene 5a and 5b is described. The phosphorus atoms in (S)-(−)-5b are shown to be slightly more basic than the phosphorus atoms in (S)-BINAP by comparing the magnitude of the 1J (31P–77Se) coupling constant in their respective diselenide derivatives. (S)-(−)-5b behaved similarly to (S)-BINAP in asymmetric Heck reactions.  相似文献   

6.
Schizandra chinesis(wuweizi)has long been used in Chinese herbal medicine.Schisandrin C,as a constituent of Schizandra chinesis,shows various pharmacologicalactivities1.The similar compound,dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethenedi-oxy-biphenyl-2,2′-dicarboxylate(α-DDB),discovered by Xie2,3et al.in the investing-ation of schisandrin C,and some derivatives have also exhibited anti-HIV and anti-HBVactivity4.Further study of this kind of biphenyls has attracted considerable attenti…  相似文献   

7.
A method was developed for the synthesis of 2-alkyl(aryl)-1,2-dihydro-2,3-biquinolines, based on the addition of organolithium compounds to 2,3-biquinoline in the presence of tetramethylethylenediamine. Their oxidation with manganese dioxide led to 2-alkyl(aryl)-2,3-biquinolines.For Communication 2, see [1].Stavropol State University, Stavropol 355009, Russia. Russian Chemical-Technology University, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 350–354, March, 1998.  相似文献   

8.
In this paper we present and discuss experimental results to evaluate performances and aging behaviour of two Hole Transporting Material (HTM), TPD and NPD, in Organic Light Emitting Device (OLED) with structure: ITO/HTM/Alq3/Al. For each of these HTMs, devices with several thicknesses have been built, to measure and emphasize behaviours of material-geometry combinations. Electro-optical properties have been measured to estimate and compare brightness, power efficiency and aging decays.  相似文献   

9.
《合成通讯》2013,43(20):3527-3536
Abstract

The first total synthesis of (±)-7,3′-dihydroxy-4′-methoxyflavan (1) and (±)-7,4′-dihydroxy-3′-methoxyflavan (2), along with the synthesis of (±)-7,4′-dihydroxyflavan (3), three naturally occurring flavans, were described. The key step is the cyclization of 1,3-diaryl-1-propanol by BF3·Et2O.  相似文献   

10.
Summary The title compound3 was prepared from 8,8-Bis(bromomethyl)-1,1-binaphthyl (1) in two steps in approx. 10% overall yield. The crystal structure of the intermediate phosphinoxide2 was determined. Attempts to prepare chelate complexes of3 with Ni(II) or Pd(II) failed.
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11.
Zusammenfassung Im Anschluß an kürzlich erschienene Arbeiten über Synthesen von 3-(N-Methyl-2-piperidyl)-chinolizidin, einer Verbindung von der gleichen Struktur wie sie dem Alkaloid Pusillin zukommen soll, wird über eine eigene Synthese zweier stereoisomerer Verbindungen dieser Konstitution berichtet.  相似文献   

12.
通过(硫代)亚磷酸二酯与酮核苷的羰基的加成反应合成了2′位或3′位(硫代)膦酰修饰的核苷,在这一加成反应中,只检测和分离到一种异构体.文中对该异构体的构型进行了讨论.  相似文献   

13.
The thermal behavior of[Eu2(BA)6(dmbpy)2] (BA=C7H5O 2 , benzoate; dmbpy=C12H12N2, 4,4-dimethyl-2,2-bipyridine) and its kinetics were studied under the non-isothermal condition in a static air atmosphere by TG-DTG, IR and SEM methods. Thermal decomposition of [Eu2(BA)6(dmbpy)2] occurred in four consecutive stages at T P 232, 360, 455 and 495°C. The kinetic parameters were obtained from analysis of the TG-DTG curves by Achar and Madhusudanan—Krishnan—Ninan (MKN) methods. The most probable mechanisms for the first stage was suggested by comparing the kinetics parameters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

14.
15.
3′-Formyl-4′,6′-dihydroxy-2′-methoxy-5′-methylchalcone (FMC) was a natural product isolated from Cleistocalyx operculatus. A four-step synthetic strategy toward FMC and its four analogues (1b–1e) was first developed. All compounds were synthesized from commercially available 2,4,6-trihydroxyacetophenone; formylation at 3′ position under Vilsmeier–Haack conditions was followed by the introduction of a methyl group at 5′ position. The key step of selective methylation at 2′ position was achieved by trimethylsilyldiazomethane (TMSCHN2). Then substituted aromatic aldehydes were condensed through Claisen–Schmidt reaction in the presence of potassium hydroxide. All structures were confirmed by 1H NMR, 13C NMR, and high-resolution mass spectra. FMC and analogues were screened for their antiproliferative activity.  相似文献   

16.

The reaction of M(OAc)2 with 2,2′-bis(2-hydroxybenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl (H2L1) allows the synthesis of 2,2′-bis(2-oxidobenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl complexes of Cu(II) (CuL1), Co(II) (CoL1) and Ni(II) (NiL1) that were characterized by elemental analysis, FTIR spectroscopy and for CuL1 also by X-ray crystallography verifying a tetradentate binding mode of L1 via an (ONNO) motif of the two phenolic oxygen atoms and two azomethine nitrogen atoms. Recrystallization from a solvent mixture of dichloromethane and methanol promotes the formation of methanol adducts. Different binding modes of the methanol–complex were investigated using density functional theory calculations and binding energies, and thermodynamic data of the interaction are reported. The results show that the favored interaction occurs when the methanol molecule acts as a Lewis acid weakly binding via an O–H···O hydrogen bridge to a phenoxide moiety leading to an elongation of the respective M–O bond.

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17.
Zusammenfassung B-Chlorborazole reagieren mit Alkalimetallen unter Kondensation. Aus Monochlorborazolderivaten entstehen so B,B-Biborazyle, aus Dichlorborazolen B,B-Polyborazylene und aus Trichlorborazolen vernetzte Polymere von guter thermischer Beständigkeit.Mit 3 AbbildungenHerrn Prof. Dr.F. Halla zum 80. Geburtstag gewidmet.  相似文献   

18.
IntroductionSince C. W. Tang firstly reported theelectroluminescence of 8- hydroxyquinolinealuminium[1] ,much attention has been paid to themetal complexes as electro- luminescent materials.Based on a series of experimental data,it has beenknown that the electroluminescence of metalcomplexes with heterocyclic ligands containing Nand O elements mainly results from the tripletstatetransition.For some transitional metal complexes,there exist the transitions from metal to ligand( MLCT) at thei…  相似文献   

19.
通过Heck反应,以4,4′-二碘联苯和丙烯酸为原料,壳聚糖负载钯为催化剂,合成了3,3′-(1,1′-二苯基-4,4′-二基)-二丙烯酸.考察了反应温度、时间、原料配比等因素对产率的影响.结果表明最佳反应条件为:反应温度为100℃,时间为20h,原料配比为1∶3.测试了壳聚糖负载钯催化剂的重复使用性能,并用IR、1 H NMR和MS对产物进行了表征.  相似文献   

20.
An unsaturated 2-methoxy-substituted 1-O-alkylglycerol, (Z)-(2′R)-1-O-(2′-methoxynonadec-10′-enyl)-sn-glycerol, a new analog of bioactive ether lipids, was synthesized from oleic acid and 2,3-isopropylidene-sn-glycerol. The two key steps of this synthesis were the conversion of oleyl aldehyde to a monounsaturated epoxide using Matteson’s method followed by hydrolytic kinetic resolution and a nucleophilic epoxide opening by 2,3-isopropylidene-sn-glycerol in the presence of potassium tert-butoxide in anhydrous DMF, which appeared to be a good reagent for this purpose. Furthermore, the diol by-product of the HKR process was also easily converted back to the starting epoxide thus almost doubling the amount of target molecule.  相似文献   

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