Synthesis and properties of azoles and their derivatives. 57. Unexpected results of 3-nitropropene-1 [2+3] cycloaddition to C,C,N-triphenylnitrone

[2+3] Cycloaddition of 3-nitropropene-1 with C,C,N-triphenylnitrone leads to a mixture of 5-nitromethyl-2,3,3-triphenylisoxazolidine and 5-methyl-4-nitro-2,3,3-triphenylisoxazolidine. The results obtained can be explained assuming that 3-nitropropene-1 isomerizes to 1-nitropropene-1 under reaction conditions. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1545–1548, October, 2006.     

Acid-mediated three-component aza-Diels-Alder reactions of 2-aminophenols under controlled microwave heating for synthesis of highly functionalized tetrahydroquinolines. Part 9: Chemistry of aminophenols

The aza-Diels-Alder reactions of two 2-aminophenols in combination with six substituted benzaldehydes and two electron-rich cyclic alkenes were investigated under controlled microwave heating. The reactions were carried out in the presence of a catalytic amount of CF₃CO₂H in MeCN at 60 °C for 15 min, affording highly functionalized 8-hydroxy-1,2,3,4-tetrahydroquinolines in 39-59% isolated yields and in 36:64-16:84 diastereomer ratios in favor of the trans isomers. The microwave-heated three-component aza-Diels-Alder reactions completed in significantly reduced reaction time to give the same level of chemical yield and diastereomer ratio obtained from the room temperature reaction.     

1,3-Dipolar cycloaddition of azomethine ylides generated from aziridines in supercritical carbon dioxide

The 1,3-dipolar cycloaddition of azomethine ylides with DMAD in supercritical carbon dioxide is reported. The photolysis reaction conditions were optimized with a suitable adjustment of pressure, temperature, irradiation time and co-solvent concentration leading to a more efficient reaction than in neat acetonitrile. Similar results were observed using thermal reaction conditions. Supercritical carbon dioxide with a minute co-solvent addition is shown to be a very efficient medium for promoting this type of cycloadditions.     

Regio- and stereo-selective synthesis of multi-substituted 3-pyrrolines

A regio-and stereo-selective synthesis of multi-substituted 3-pyrrolines has been developed.The multi-substituted 3-pyrrolines were synthesized in good yields by 1,3-dipolar cycloaddition of methyl 2-(phenylselanyl)acrylate with azomethine ylides,followed by N-acylation and oxidation-elimination of phenylseleno group.     

A New and Efficient Synthesis of Wedelolactone Derivatives

A new and facile method based on an intermolecular cycloaddition was described for the synthesis of wedelolactone derivatives.     

TM610高次模圆柱谐振腔的模拟研究

 根据电磁场理论设计了S波段TM610高次模圆柱谐振腔。运用HFSS，ISFELD3D， CST-MS及MAFIA软件计算了该谐振腔中TM₆₁₀及其附近模式的电磁场分布、谐振频率及模式间隔。计算表明：TM₆₁₀模式的电磁场集中在漂移管头周围的区域，谐振腔中心处无电磁场分布。根据TM₆₁₀模式的特点，采取了在腔中心放置铁氧体微波吸收材料的方法来抑制杂模。HFSS模拟表明：腔内吸收材料可消除TM₅₁₀模式外大部分杂模的影响。采用了在主谐振腔外加耦合吸收腔的方法来抑制TM₅₁₀模式，该吸收腔基模TM₀₁₀的谐振频率等于TM₅₁₀的谐振频率。模拟表明：TM₅₁₀模式的大部分能量可以被吸收腔内的铁氧体材料衰减掉，Q值从15 604下降到571。     

Facile Functionalization of Multilayer Fullerenes (Carbon Nano‐Onions) by Nitrene Chemistry and “Grafting from” Strategy

Facile functionalization of multilayer fullerenes (carbon nano‐onions, CNOs) was carried out by [2+1] cycloaddition of nitrenes. The products were further derivatized by using the “grafting from” strategy of in situ ring‐opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Using one‐step nitrene chemistry with high‐energy reagents, such as azidoethanol and azidoethyl 2‐bromo‐2‐methyl propanoate, in N‐methyl‐2‐pyrrolidone at 160°C for 16 h, hydroxyl and bromide functionalities were introduced onto the surfaces of CNOs. These hydroxyl CNOs (CNO‐OH) and bromic CNOs (CNO‐Br) were extensively characterized by various techniques such as thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), Raman spectroscopy and X‐ray photo electron spectroscopy (XPS). TGA measurements indicated that the surface hydroxyl and bromide group density reached 1.49 and 0.49 mmol g^?1, respectively. The as‐functionalized CNOs showed much better solubility in solvents than pristine CNOs. The CNO‐OH were also observed to fluoresce at λ=453 nm in water. The CNO‐OH and CNO‐Br can be conveniently utilized as macroinitiators to conduct surface‐initiated in‐situ polymerizations. Poly(ε‐caprolactone) (PCL, 45wt %) and polystyrene (PS, 60 wt%) were then grafted from surfaces of CNOs through the ROP of ε‐caprolactone with the macroinitiator CNO‐OH and the ATRP of styrene with the macroinitiator CNO‐Br, respectively. The structures and morphology of the resulting products were characterized by ¹H NMR, scanning electron microscopy (SEM), TEM, and atomic force microscopy (AFM). The polymer functionalized CNOs have good solubility/dispersibility in common organic solvents. The facile and scalable functionalization approaches can pave the way for the comprehensive investigation of chemistry of CNOs and fabrication of novel CNO‐based nanomaterials and nanodevices.