Convenient One‐Pot Synthesis of 2,5‐Disubstituted Oxazoles via a Catalytic Oxidative Dehydrogenation of F3CSO3H·SiO2‐DDQ/CuCl2/LiCl

A facile one‐pot synthesis of 2,5‐disubstituted oxazoles was developed via cyclization of aldoximes and phenylacetylene then dehydrogenation oxidation. 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone was studied for the selective oxidation of oxazolines using Cu²⁺/Li⁺ as catalyst and O₂ as indirect oxidant. The reaction results showed that this catalyst system can effectively catalyze the oxidation of oxazolines to the corresponding oxazoles. Thus, a variety of polysubstituted oxazoles was easily synthesized in high yields by catalytic oxidation of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone/CuCl₂/LiCl/O₂.     

Facile One‐Pot Synthesis of Oxazolidin‐2‐ones from Phenyl 2‐Hydroxyalkyl Selenides

A novel, convenient, efficient, three‐step, one‐pot synthesis of 2‐oxazolidinones from phenyl 2‐hydroxyalkyl selenides was developed. Using this methodology, 2‐oxazolidinones are obtained in good yields (76–85%) by reaction of phenyl 2‐hydroxyalkyl selenides with benzoyl isocyanate and subsequent oxidation/cyclization, followed by hydrolysis with hydrochloric acid solution.     

Highly Selective Synthesis of Methyl 1-Phenyl-1-(9-hydro-)fullerenylacetate

Isomerically pure methyl 1-phenyl-1-(9-hydro-)fullerenylacetat is synthesized in 75% yield by the reaction of C₆₀ with the carbanions of methyl phenylacetate in C₆H₆/THF mixed solvent under a purified N₂ atmosphere at 20°C.     

Study on the Interaction Between Bovine Serum Albumin and Potassium Perfluoro Octane Sulfonate

The interactions between potassium perfluorooctanesulfonate (PFOS) and bovine serum albumin (BSA) were studied by fluorescence spectroscopy. The association constants between PFOS and BSA were obtained by fluorescence enhancing and fluorescence quenching respectively. Furthermore, fluorescence quenching was studied at different temperatures, and the binding constant was also determined by the method of fluorescence quenching. According to the thermodynamic parameters, the main binding force could be judged. The experimental results revealed that BSA and PFOS had strong interactions. The mechanism of quenching belonged to dynamic quenching and the main sort of binding force was hydrophobic force. IR-spectra proved the interaction changed the conformation of BSA.     

Interaction of Metal–Dipeptide Complex with Ninhydrin in the Absence and Presence of Conventional CTAB Surfactant

The present work is aimed at studying the interaction between copper-glycyltyrosine [(Cu(II)-Gly-Tyr)]⁺ and ninhydrin in water and in micelles formed by cetyltrimethylammonium bromide (CTAB) using spectrophometric measurements at 80°C and pH 5.0. The order of reaction remains the same in the two systems, that is, first- and fractional-order kinetics with respect to [Cu(II)-Gly-Tyr]⁺ and [ninhydrin], respectively, in the excess of ninhydrin over [Cu(II)-Gly-Tyr]⁺. It was observed that the product formed is same in both the media. The reaction is catalyzed by CTAB, and the maximum rate enhancement is about three fold. Quantitative kinetic analysis of k_ψ–[CTAB] data was explained in terms of pseudo-phase of the micelles (assuming the association/incorporation of both the reactants at the micellar surface).     

Surface-Modified Sb2S3 Nanoparticles and Their Tribological Behaviors in Liquid Paraffin

Sb₂S₃ nanoparticles surface-modified with S-tetradecyl N, N-dihydroxyethyl dithiocarbamate (C₁₄DTC-Sb₂S₃) have been synthesized via extraction of Sb₂S₃ colloidal particles from ethylene glycol into toluene in the presence of C₁₄DTC. The obtained products were characterized by high-resolution transmission electron microscope (HRTEM) and Fourier transformation infrared (FTIR), and their tribological behaviors as an additive in liquid paraffin were investigated using a four-ball tribometer. The results show that C₁₄DTC-Sb₂S₃ nanoparticles can significantly improve the friction reduction, anti-wear, and load-carrying properties of base oils. The preliminary lubrication mechanism was discussed based on the SEM and XPS investigation of the rubbed surfaces.     

碳酸钾催化的铁基氧载体煤催化化学链燃烧

研究了K₂CO₃催化剂及惰性担体对铁基氧载体煤化学链燃烧的影响.实验结果表明,K₂CO₃的添加可明显促进铁基氧载体与煤之间的反应速率,其原因可归结为从氧载体上迁移到煤颗粒上的K₂CO₃对煤-CO₂气化步骤的催化作用(该步骤为整个还原过程的速率控制步骤);由于K₂CO₃本身的促熔效果及加入K₂CO₃后导致的剧烈氧化还原反应,可以发现,K₂CO₃会增大铁基氧载体的烧结;不同惰性担体对铁基氧载体与煤的反应性影响不大,这是由于惰性担体对还原速控步没有影响;K₂CO₃在多循环化学链燃烧过程中依然可以保持一定的催化活性,另外由于催化剂的流失与失活,使得氧载体的反应活性有所下降.     

Cu-V-O氧化物催化燃烧甲苯的活性和抗硫性

采用溶胶-凝胶法制备一系列不同Cu/V比例的Cu-V-O催化剂,利用XRD、BET、H₂-TPR等手段对催化剂进行了表征,并考察其催化燃烧甲苯的活性和抗硫性。结果表明,适量的Cu掺杂会提高催化剂比表面积,而且Cu-V可以形成Cu₃V₂O₈晶型结构,使V₂O₅晶格氧活动增加,提高催化剂氧化-还原能力。其中,Cu_0.15V_0.85催化剂表现出最佳的活性和抗硫性;通过TiO₂负载可以进一步提高催化剂对甲苯的催化燃烧活性和抗硫性。     

Raney Ni催化二亚糠基丙酮加氢制取长链烷烃前驱体的特性研究

采用Raney Ni为催化剂,考察了反应温度、压力、时间和溶剂对二亚糠基丙酮加氢制取长链烷烃前驱体催化性能的影响。结果表明,Raney Ni对二亚糠基丙酮具有很好的低温加氢性能,升高反应温度和压力均有利于加氢反应的进行,但过高的温度反而不利于加氢反应。在50℃和2.5 MPa下反应2 h,二亚糠基丙酮转化率达99.5%以上,饱和加氢产物的总选择性达到80.8%。此外,加氢中间产物的变化结果表明,二亚糠基丙酮的双键加氢容易程度为,烯键>呋喃环双键>C=O双键。Raney Ni 在甲醇溶剂中的加氢性能明显高于在四氢呋喃、环己烷或水溶剂中的加氢性能。     

基于核酸分子杂交的免疫芯片抗体固定新方法

基于核酸分子杂交原理构建了一种新型抗体固定方法.先将抗体与寡核苷酸单链交联,再将两者的复合物与固相载体表面上的互补寡核苷酸链结合,从而将抗体固定到载体的表面.在磁珠表面对该固定方法进行实验,证明了方法的可行性.以本方法构建了针对转基因Bt Cry1Ac蛋白的免疫芯片,用Cy3标记二抗对其探针固定效果进行分析,并且在芯片上对Bt Cry1 Ac蛋白进行梯度浓度检测试验.结果表明,以本方法构建的抗体芯片,探针分布具有良好的特异性;探针层分布均匀,非特异吸附小;检测灵敏度达到0.01 ～ 0.05 μg/L;此外,通过杂交核酸双链的解离成功实现了芯片的再生,有助于解决传统抗体固定方法中芯片不可再生的问题.