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991.
992.
A simple and convenient Brønsted acid (HNO3)-catalyzed tandem reaction of α-ketoesters with primary or secondary aromatic amines for the synthesis of polysubstituted 1,2-dihydroquinolines has been developed via a tandem process, which has the advantages of ready availability of catalyst, operation simplicity, atom efficiency as well as low toxicity. In particular, tricyclic dihydroquinolines, generally prepared with multi-processes, could also be constructed in this one-pot procedure. 相似文献
993.
The one-pot three-component reaction for the synthesis of pyran annulated heterocycles is reported by condensing aromatic aldehydes, ethyl cyanoacetate, or malononitrile and C-H activated acidic compounds in the presence of catalytic amount of 4-(dimethylamino)pyridine (DMAP) in ethanol under reflux conditions. The significant features of the present protocol are simple, environmentally benign, high yields, non-aqueous work-up procedure, no chromatographic separation and recyclability of the catalyst. 相似文献
994.
Yasemin Oztekin Zafer Yazicigil Ali Osman Solak Zafer Ustundag Zeynel Kilic Selen Bilge 《Surface and interface analysis : SIA》2011,43(5):923-930
Modification of glassy carbon (GC) surfaces with phenanthroline derivatives (PDs) such as 5‐amino‐1,10‐phenanthroline (5AP) and 5,6‐diamino‐1,10‐phenanthroline (56DAP) is described in this study. Surface modification experiments were performed by cyclic voltammetry (CV) scanning from + 1.2 to + 2.7 V at scan rate of 100 mV/s applying 30 potential scans in acetonitrile (CH3CN) containing 1 mM PDs and 100 mM tetrabutylammoniumtetrafluoroborate (TBATFB). The presence of PDs on GC electrode was confirmed using CV, electrochemical impedance spectroscopy (EIS), contact angle measurements and ellipsometry and comparing with the results of bare GC electrode. A mechanism was proposed for the electrochemical modification of the GC electrode surface with PDs. The structure of the 5AP and 56DAP films was also discussed in the light of electrochemical and spectroscopic data. The complex‐forming ability of the modified surfaces against metal cations was investigated by square‐wave voltammetry (SWV). It was shown that surfaces having 1,10‐phenanthroline ligands with different functional groups were quite useful for the determination of transition metal ions. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
995.
B. Machura A. ?witlicka D. Tabak J. Polański 《Journal of organometallic chemistry》2011,696(3):731-738
The molecular structure of 7-acetamido-2-methyl-quinoline-5,8-dione has been determined and the reactivity of 7-acetamido-2-methyl-quinoline-5,8-dione (1) and 6-acetamido-2-methyl-quinoline-5,8-dione (2) towards Re(CO)5Cl has been examined. Two novel tricarbonyl rhenium complexes, fac-[Re(CO)3(7-acetamido-2-methyl-quinoline-5,8-dione)Cl]·CHCl3 (3·CHCl3) and fac-[Re(CO)3(6-acetamido-2-methyl-quinoline-5,8-dione)Cl]2·CHCl3 (4·CHCl3), have been synthesized and characterized spectroscopically and structurally. The electronic spectrum of 3 was investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ. 相似文献
996.
Andrey Semioshkin Vladimir Bregadze Anna Ilinova Irina Lobanova 《Journal of organometallic chemistry》2011,696(23):3750-3755
New 2′-deoxyadenosine and adenosoine modifications: 8-[(2-dimethylaminoethyl)amino]-2′-deoxyadenosine and 8-[(2-dimethylaminoethyl)amino]adenosine were prepared and their reactivity towards cyclic oxonium adducts of closo-dodecaborate and cobalt-bis-dicarbollide was studied. The cleavage reactions of clusters oxonium rings by N,N-dimethylanio group of modified nucleosides led to the first [B12H12]2− and new [Co(C2B9H11)2]− conjugates with adenosine and 2′-deoxyadenosine respectively. The proposed methodology provides a convenient route for the synthesis of libraries of boron cluster modified adenosine and 2′-deoxyadenosine derivatives for biological screening. 相似文献
997.
Hui ChenDaqing Shi 《Tetrahedron》2011,67(31):5686-5692
An efficient one-pot synthesis of spiro[indoline-3,4′-pyrazolo[3,4-e][1,4]thiazepine] dione derivatives via three-component reaction of 5-amino-3-methylpyrazole, isatin, and thioacid is described. This new protocol produces novel heptacyclic spirooxindole derivatives in good yields in comparison to conventional pentacyclic compounds. This method proceeds through a 3-(5-aminopyrazol-3-yl)-3-hydroxy-2-oxindoline intermediate (Baylis-Hillman type adduct), unlike 3-indolylimine (the intermediate like Shiff-Bases) as in conventional methods. The structure of one representative compound has been confirmed by X-ray diffraction analysis. 相似文献
998.
This work deals with the synthesis of piperidine and hydroxypiperidine analogs of nucleosides. Starting from commercially available 3-hydroxypiperidine, proline or 4-hydroxyproline, a series of piperidine derivatives of both purine and pyrimidine nucleobases was prepared. Various methods of nucleobase attachment were evaluated. The prepared compounds were tested for cytostatic, antibacterial, and antiviral properties but no significant activity was found. 相似文献
999.
Two coordination compounds [Pb4(BDT)3(OH)2(H2O)4]·H2O ( 1 ) and [Mn(H2O)6]·(HBDT)2·2H2O ( 2 ) [H2BDT?5,5′‐(1,4‐phenylene)bis(1H‐tetrazole)] had been hydrothermally synthesized. 1 and 2 had been characterized by single‐crystal X‐ray diffraction, IR, elemental and thermal analyses. Structural analysis reveals that 1 exhibits 2D layer structure extended through BDT with two different coordination modes rings in transverse and vertical. 2 consists of [Mn(H2O)6]2+, free HBDT and water. In addition, 1 and 2 were explored as luminescent materials and additives to promote the thermal decomposition of ammonium perchlorate by differential scanning calorimetry. 相似文献
1000.
Silica gel-supported polyphosphoric acid(PPA-SiO2) was found to be an efficient catalyst for the one-pot four-component Hantzsch condensation reaction of aryl aldehydes,dimedone,ethyl acetoacetate and ammonium acetate to afford the corresponding polyhydroquinoline derivatives in high yields.The main advantages of the present approach are short reaction times,clean reaction profiles,simple experimental and workup procedures. 相似文献