Synthesis and In Vitro Antiviral Activities of Some New 2-Arylthiomethyl-4-tertiaryaminomethylsubstituted Derivatives of 6-Bromo-3-ethoxycarbonyl-5-hydroxyindoles

Some new derivatives of 3-ethoxycarbonyl-6-bromo-5-hydroxyindoles were designedand prepared, their antiviral activity were determined in cell culture with virus cytopathic effect assay. The results showed compound Ⅶ b, Ⅶ h exhibited potential antiviral activity.     

原位氧化还原沉淀水热合成法制备LixMn2O4尖晶石

Li xMn2O4尖晶石是新一代的锂离子二次电池正极材料 [1], 其合成方法对材料的电化学性质影响很大[2].常规合成大多采用高温固相反应法, 此法具有反应温度高, 反应时间长, 容易产生缺陷和产物不纯净等缺点, 导致所合成的锂离子二次电池正极材料的性能较差. 目前用水热合成法制备电池正极材料Li xMn2O4尖晶石尚未见文献报道. 本文在常规水热合成法的基础上采用原位氧化还原沉淀水热合成法 [3]制备前驱物, 该法合成条件更温和, 而且使材料的综合性能得到了改善和提高.      

Chiral Phosphinophenyloxazolines Bearing Alkoxymethyl Substituents: Synthesis and Application in the Palladium Catalyzed Allylic Substitution Reactions

The chiral phosphine‐oxazoline ligands 3 and 4 bearing 4‐alkoxymethyl substituents on the oxazoline ring with (R)‐configuration were prepared from L‐serine methyl ester in 66% and 33% yields, respectively. Along this synthetic pathway, the β‐hydroxylamides derived from L‐serine methyl ester and 2‐halobenzoyl chlorides were expediently converted to the corresponding oxazolines by using diethylaminosulfur trifluoride as the activation agent. Potassium diphenylphosphide was the reagent of choice for replacing the bromine atom on the phenyl ring, giving the desired oxazoline‐phosphine ligands 3 and 4 . Together with [Pd(η³‐allyl)Cl]₂, ligands 3 and 4 induced an enantioselective allylic substitution reaction of 1,3‐diphenyl‐2‐pro‐penyl acetate by dimethyl malonate. Although ligands 3 and 4 exhibit the (R)‐configuration, differing from the (S)‐configuration of Pfaltz‐Helmchen‐Williams phosphine‐oxazoline ligands, all these ligands led to the same enantiotopic preference in the allylic substitution reaction. To facilitate the recovery and reuse of the phosphine‐oxazoline ligand, immobilization on Merrifield resin was attempted, albeit in low loading.     

Molecular-dynamics studies of bending mechanical properties of empty and C60-filled carbon nanotubes under nanoindentation

This paper utilizes molecular-dynamics simulations to investigate the mechanical characteristics of a suspended (10, 10) single-walled carbon nanotube (SWCNT) during atomic force microscopy (AFM) nanoindentation at different temperatures. Spontaneous topological transition of the Stone-Wales (SW) defects is clearly observed in the indentation process. The present results indicate that under AFM-bending deformation, the mechanical properties of the SWCNT, e.g., the bending strength, are dependent on the wrapping angle. In addition, it is also found that the radial dependence of the reduced formation energy of the SW defects is reasonably insensitive only for the small tubes. However, for tube diameters greater than 2.4 nm [corresponding to the (18, 18) CNT], the SW defects tend to be more radius sensitive. The results indicate that the bending strength decreases significantly with increasing temperature. This study also investigates the variation in the mechanical properties of the nanotube with the density of C60 encapsulated within the nanotube at various temperatures. It is found that, at lower temperatures, the bending strength of the C60-filled nanotube increases with C60 density. However, the reverse tendency is observed at higher temperatures. Finally, the "sharpest tip" phenomena between the probe and the tube wall and the elastic recovery of the nanotube during the retraction process are also investigated.     

ω-氟砜基氟烷基格氏试剂的制备及其反应

合成氟烷基酮的通用方法是将全氟烷基金属试剂与羰基类化合物反应。但对于ω位带有官能团的全氟烷基金属试剂的研究,唯一的例子是:     

Development and validation of a high-performance liquid chromatography-electrospray ionization-mass spectrometry assay for the determination of zaleplon in human plasma

In this paper, a sensitive and rapid chromatographic procedure using a selective analytical detection method (electrospray ionization-mass spectrometry in selected-ion monitoring mode) in combination with a simple and efficient sample preparation step is first presented for the determination of zaleplon in human plasma. The separation of the analyte, internal standard, and possible endogenous compounds are accomplished on a phenomenex Luna 5-microm C8(2) column (250- x 4.6-mm i.d.) with methanol-water (75:25, v/v) as the mobile phase. In order to optimize the mass detection of zaleplon, several parameters such as ionization mode, fragmentor voltage, m/z ratios of ions monitored, type of organic modifier, and eluent additive in the mobile phase are discussed. An internal standard is selected to guarantee the quantitative accuracy. Each analysis takes less than 6 min. The calibration curve of zaleplon in the range of 0.1-60.0 ng/mL in plasma is linear with a correlation coefficient of > 0.9992, and the detection limit (s/n = 3) is 0.1 ng/mL. The within- and between-day variations (relative standard deviation) in the zaleplon plasma analysis are less than 2.4% (n = 15) and 4.7% (n = 15), respectively. The application of this method is demonstrated for the analysis of zeleplon plasma samples in a Phase-I human pharmacokinetic study.     

提高烃类燃料热沉的研究进展

吸热型烃类燃料是一种热安定性好、可以利用其化学热沉的燃料,其热沉能够满足高超音速飞行的需要。本文论述了燃料热安定性、催化脱氢、催化裂解、引发裂解、超临界裂解等对吸热型烃类燃料热沉的影响,重点论述了引发裂解在吸热型烃类燃料中的裂解优势,提出引发裂解在高超音速飞行器上具有诱人的应用前景。     

Syntheses and structural characterizations of Fe_4S_4 cubane-like cluster compounds containing cycloalkylthiolate ligands

In a reaction system consisting of FeCl2,tetrathiometallate and cycloalkylthiolate,two Fe4S4 cubane-like cluster compounds were obtained with the following crystallographic data:(PhCH2NMe32[Fe4S4 (SC5H9)4](Ⅰ),monoclinic space group P21/c,a=1.6327(4),6=1.1229(3),c=2.802 5( 10) nm,β=94.63(2)°,Z=4,and R=0.074; (Et4N)2[Fe4S4(SC6H11)4](Ⅱ),tetragonal space group I42m,a=1.16705(9),b=1.167 06(2),c=2.063 26(5) nm,Z=2,Dabs=1.28 g/cm3,and R=0.078 The participation of cy-cloalkylthiolate ligand does not obviously arouse the change of the Fe4S4 core structure.Meanwhile,the influence of the cation on the structural symmetry of the Fe4S4 cluster dianion is also discussed.     

DIRECT SOMATIC EMBRYOGENESIS AND PLANT REGENERATION FROM PROTOPLAST-DERIVED CELLS OF WHEAT (Triticum aestivum L.)

Protoplasts were isolated from embryogenic calli derived from immature embryos ofwheat (Triticum aestivum L. cv. Jinan 177). The protoplasts were cultured in NMB mediumsupplemented with 1mg/L 2,4- D and 500mg/l casein hydrolysate (CH). The regenerated cellsfrom protoplasts divided to form somatic embryos directly. The somatic embryos grown to1.5- 2 mm in size directly developed into complete plants on solid MB medium without hor-mones.     

4-二甲氨基吡啶催化合成含氟苯甲酸糖酯

以4－二甲氨基吡啶为催化剂由含氟苯甲酸与溴代乙酰糖催化酯化合成了4个新的含氟苯甲酸糖酯。其结构经IR，^1H NMR和MS确认，多数还作了^13C NMR测定。