Preparation of isoprostanes and neuroprostanes

A new approach to isoprostanes and neuroprostanes featuring cis-dialkyl stereochemistry at the cyclopentane ring has been developed by employing an intramolecular cross-coupling reaction of an alkyl iodide and a tethered alkenylsiloxane for stereoselective installation of a functionalized omega-side chain.     

A nanoscale vesicular polydiacetylene sensor for organic amines by fluorescence recovery

We report a nanoscale lipid membrane-based sensor of conjugated polydiacetylene (PDA) vesicles for fluorescence detection of organic amines. The vesicle sensor was constructed by incorporation of a BODIPY fluorescent dye into the PDA vesicles. The fluorescent properties of the resulting vesicles can be manipulated by adjusting lipid components, and are controlled by environmental and solution conditions. The fluorescence of the BODIPY dye was significantly quenched in the polymerization of diacetylene lipid vesicles by a UV irradiation process. However, it was sufficiently recovered by external stimuli such as a hike of solution pH. The fluorescence recovery process was reversible, and a decrease in solution pH resulted in repeated quenching. The reported system transforms an external stimulus into a large fluorescence intensity change, demonstrating great potential in developing new signal reporting method for biosensor design. The quench-recovery phenomenon of the BODIPY-PDA is believed to be related to the energy transfer between the dye and the PDA conjugate backbone. The vesicle sensor was applied for detecting an organic amine, triethylamine (TEA) and a large linear relationship was obtained between the increase in fluorescence intensity and the concentrations of TEA. The detection limit of TEA by vesicle sensors using fluorescence recovery was found to be 10 μM.     

Synthesis of poly(<Emphasis Type="Italic">N</Emphasis>-methylolacrylamide)/polymethylacrylamide hybrids via frontal free-radical polymerization

In this study, poly(N-methylolacrylamide)/polymethylacrylamide (PNMA/PMAA) hybrids were produced successfully by frontal free-radical polymerization at ambient pressure. In a typical run, the appropriate amounts of reactants (N-methylolacrylamide, NMA; methylacrylamide, MAA) and initiator (ammonium persulfate) were dissolved in dimethyl sulfoxide at ambient temperature. Frontal polymerization (FP) was initiated by heating the wall of the tube with a soldering iron, and the resultant hot fronts were allowed to self-propagate throughout the reaction vessel. Once initiated, no further energy was required for polymerization to occur. The dependences of the front velocity and front temperature on the initiator concentration, reactant dilution, and NMA/MAA components were thoroughly investigated. The front temperatures were between 69 and 116 °C, depending on the persulfate concentration. We have also investigated the FP of PNMA/PMAA hybrids with N-methyl-2-pyrrolidone as solvent. Results show that FP can be exploited as a means for the preparation of PNMA/PMAA hybrids with the potential advantage of higher throughput compared to the traditional mode.     

OUH体系的结构和分析势能函数

采用密度泛涵B3LYP方法优化出了OUH分子的各种结构，确定了最稳定构型和离解能，以及它们的谐性力常数，并导出双原子分子UH,UO的Murrell-Sorbie势能函数及其光谱数据。采用多体项展式方法，导出OUH(X^4A')基态分子的分析势能函数，获得OUH(X^4A')体系的势能面，考察了这个势能函数的基本性质，正确地复现出OUH分子的平衡结构特征，结果表明：U+OH,O+UH,H+UO的反应均为无阈能的放热能反应。为进一步探讨OUH体系的反应动力学过程打下了基础。     

手性钛锆化合物在不对称合成中的应用

本文综述了近年来手性钛锆化合物在不对称合成中的应用, 特别是手性柄型金属钛和锆化合物在不对称合成中的应用。对这类催化剂的特点和前景作了简要介绍。     

One-pot oxidation of sulfides to sulfones by reusable heterogeneous ruthenium catalyst in the presence of molecular oxygen

A reusable solid catalyst, MnFe_1.8Cu_0.15Ru_0.05O₄, has been developed as an effective catalyst for the aerobic oxidation of sulfides and sulfoxides to sulfones. The ruthenium modified spinel catalyst is the first example reported for such reaction under mild condition with molecular oxygen as the only oxidant. The oxidation reaction proceeded via an electrophilic attack of the oxygen atom of the catalyst on the electron-rich sulfur atom of the substrate.     

Lanthanum heterocyclic Schiff-base complex initiated ring-opening polymerization of ε-caprolactone

Lanthanum complex supported by the heterocyclic Schiff-base ligand of N-(2-pyridyl)-3,5-di-tert-butyl-salicylaldimine was prepared and employed for the ring-opening polymerization(ROP)ofε-caprolactone(ε-CL).The polymers obtained with this initiator showed a unimodal molecular weight distribution implied that only one active species was present.Mechanism study revealed that the polymerization proceeds via acyl-oxygen bond cleavage.     

Phenyl and Phenylethyl Glycosides from Picrorhiza scrophulariiflora

Three new phenyl glycosides, scrophenoside A ( 1 ), B ( 2 ), and C ( 3 ), and two new phenylethyl glycosides, scroside D ( 4 ) and scroside E ( 5 ), were isolated from the stem of Picrorhiza scrophulariiflora Pennell (Scrophularlaceae), besides five known compounds. On the basis of spectroscopic evidence, the structures of the new compounds were elucidated as 4‐acetyl‐2‐methoxyphenyl 6‐O‐[4‐(β‐D ‐glucopyranosyloxy)vanilloyl]‐β‐D ‐glucopyranoside ( 1 ), 4‐acetylphenyl 6‐O‐[(E)‐p‐coumaroyl]‐β‐D ‐glucopyranoside ( 2 ), 4‐[(1R)‐ and (1S)‐1‐hydroxyethyl]‐2‐methoxyphenyl β‐D ‐glucopyranoside ( 3a and 3b , resp.), 2‐(3,4‐dihydroxyphenyl)ethyl O‐β‐D ‐glucopyranosyl‐(1→3)‐4‐O‐[(E)‐feruloyl]‐β‐D ‐glucopyranoside ( 4 ), and 2‐(3,4‐dihydroxyphenyl)ethyl O‐β‐D ‐glucopyranosyl‐(1→3)‐6‐O‐[(E)‐feruloyl]‐β‐D ‐glucopyranoside ( 5 ).     

4,4’-一氧二（苯胺灵）的合成和晶体结构

通过4,4’-一氧二（异氰酸苯酯）与异丙醇加成反应，合成标题化合物 4,4’-一氧二（苯胺灵）(Ⅰ) (C20H24N2O5, Mr=372.41)，并用X射线衍射、红外光谱、13C核磁共振、电子轰击质谱和元素分析对标题化合物进行表征. 晶体属于三斜晶系，空间群为P1晶体学参数为: a=0.85107(17), b=0.91164(18), c=1.45701(3) nm, α=80.44(3)°, β=85.25(3)°, γ=62.88(3)°, V=0.9922(3) nm3, Z=2, Dc=1.247 g•cm－3, μ(Mo Kα)=0.90 cm－1, F(000)=396.两个苯环平面之间的夹角为62.06° (0.06°). 晶体结构经全矩阵最小二乘法修正，最终偏离因子R=0.0520, wR=0.1434(对可观察点).此化合物应具有广谱的生物活性.