Showing papers in "Chinese Chemical Letters in 2011"

TL;DR: Copper oxide nanoparticles showed excellent catalytic activity through three-component condensation reaction of aldehydes, malononitrile, and 4-hydroxycoumarin for the synthesis of 3,4-dihyropyrano[c]chromenes in water medium in excellent yields and very short reaction times as mentioned in this paper.

TL;DR: A series of 2,3-dihydroquinazolin-4(1 H )-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones under mild conditions as discussed by the authors.

TL;DR: 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 as discussed by the authors.

TL;DR: An efficient solvent free method for the synthesis of various 3,4-dihydropyrimidin-2(1H)-one/thiones in excellent yields using sulfonated β-cyclodextrine as recyclable catalyst is described in this paper.

TL;DR: In this article, 2,3-Dihydroquinazolin-4(1H)-one derivatives are synthesized via a one-pot, three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica-bonded N-propylsulfamic acid (SBNPSA) in refluxing ethanol.

TL;DR: In this paper, 2,3-Dihydroquinazolin-4(1H)-ones have been synthesized in the high to excellent yields via condensation of 2-aminobenzamide with aldehydes and ketones in the presence of catalytic amount of ZrCl4 in EtOH at room temperature.

TL;DR: In this article, a microwave assisted efficient Hantzsch reaction via four-component coupling reactions of tetrazolo[1,5- a ]quinoline-4-carbaldehyde, dimedone/cyclohexane-1,3-dione, ethyl/methyl acetoacetate and ammonium acetate was described as the preparation of polyhydroquinolines.

TL;DR: In this paper, a facile microwave-assisted procedure for synthesis of novel fluorinated pyrazolo[3,4-d]pyrimidine derivatives containing 1, 3, 4-thiadiazole is described.

TL;DR: In this paper, a simple, rapid, efficient and environment-friendly method for the determination of trace copper in cereal samples was developed by using dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) followed by flame atomic absorption spectrometry.

TL;DR: Nano-TiO 2 as an eco-friendly and efficient nanocatalyst was applied for quinoxaline preparation with improved yield in this paper, where diketones and 1,2-diamines were condensed in the presence of catalyst at room temperature.

TL;DR: In this article, 2-substituted 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst was synthesized in high yield.

TL;DR: In this paper, N-alkylation of sulfonamides can be easily realized under mild aerobic conditions by using alcohols as the alkylating reagent, giving monoalkylated sulfon amides in high yields and selectivities with water produced as the only byproduct.

TL;DR: In this article, 4-Arylmethylidene-4,5-dihydro-3-phenylisoxazol-5-ones were synthesized by the convenient three-component reaction of ethyl benzoylacetate, hydroxylamine and aromatic aldehydes in the presence of pyridine.

TL;DR: In this article, a one-pot, three-component, and solvent free Mannich reaction was used to produce β-aminocarbonyls in good yields, and with good stereoselectivities.

TL;DR: In order to improve the stability of CO 2 capture capacity of CaO during carbonation/calcination cycles, synthetic CaO/Al 2 O 3 sorbents were synthesized by two methods: wet chemistry and sol-gelcombustion-synthesis (SGCS) to make a further comparison as discussed by the authors.

TL;DR: In this article, the combustion synthesis of α-Fe2O3 nanopowder at much lower temperature and its catalytic activity for the one-pot preparation of 3,4-dihydropyrano[c]chromenes was described.

TL;DR: In this article, a simple, fast, precise and eco-friendly analytical method for the determination of uric acid (UA) in human urine by ion chromatography (IC) was established.

TL;DR: Melamine trisulfonic acid (MTSA) can be used as an efficient and recyclable catalyst for the promotion of the synthesis of 3,4-dihydropyrimidin-2(1 H )-ones/thiones.

TL;DR: A wide range of mono-and disubstituted 2, 3-dihydroquinazolin-4(1H)-ones were obtained in high yields by condensation of isatoic anhydride, aldehydes with ammonium salts or primary amines in the presence of strontium chloride in aqueous ethanol under reflux as mentioned in this paper.

TL;DR: LiNi 0.8 Co 0.15 Al 0.05 OOH precursor, prepared by a co-oxidation-controlled crystallization method, was used to synthesize LiNi0.8 CO 0.

TL;DR: In this article, Li2SiO3 can be used for biodiesel production directly without further drying or thermal pretreatment, no obvious difference in the FAME conversion (92.4-96.7%) between the air-exposed catalyst (24-72h) and the fresh one (94.2%).

TL;DR: The condensation of o-phenylenediamines with 1,2-dicarbonyl compounds in the presence of citric acid afforded the corresponding quinoxaline derivatives in higher yields at room temperature in ethanol, and most of the reactions were completed in less than 1min this article.

TL;DR: In this article, nano-tube TiO 2 has been used as a heterogeneous catalyst for synthesis of imines in sunlight at room temperature under solvent-free conditions, and the condensation of less electrophilic carbonyl compounds with poorly nucleophilic amines was obtained in excellent yields.

TL;DR: A rapid and sensitive method to identify and analyze mixed pesticides of tricyclazole, paraquat and flusilazole by surface-enhanced Raman scattering has been reported in this article.

TL;DR: In this article, the use of p -dodecylbenzenesulfonic acid (DBSA) as a catalyst for a one-pot Biginelli reaction to afford 3,4-dihydropyrimidinone derivatives in good to excellent yields was reported.

TL;DR: In this paper, a ring-opening of epoxidized cottonseed oil with sorbitol, which is a multi-functional hydroxyl compound derived from a natural source, was investigated.

TL;DR: Schiff base-Cu(II) complex is found to be an effective catalyst for the condensation reaction of indole with aldehydes using ethanol as the solvent as mentioned in this paper.

TL;DR: In this article, the structure of prepared materials was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET) and the prepared TiO2 nanotubes were used to prepare thick film gas sensors and the gas sensing properties to various gases were tested.

TL;DR: A micelle to solvent stacking on-line sample preconcentration technique in capillary zone electrophoresis (MSS-CZE) has been developed to determine the strychnine and brucine in traditional Chinese medicine preparations as discussed by the authors.