16-脱氢孕烯醇酮醋酸酯的环境友好合成法

Instead of environmentally toxic chromium oxidant, singlet oxygen generated photcchemically was used as environmentally friendly and benign oxidizing agent to accomplish the transformation of pseudodiosgenin diacetate to diosone efficiently in a low toxic and less expensive solvent acetone. Accordingly 16-dehydropregnenolone acetate(16-DPA), an important intermediate for preparation of steroidal drugs, was prepared in good yield (75%) when photoreaction was run in acetone/acetic anhydride/pyridine system. The mild reaction condition as well as simple and environmentally friendly process made the method commercially viable and important for production of 16-DPA in industrial scale.     

钴的二苯甲酰甲烷配合物：晶体结构及其轴向置换反应

Cobalt(Ⅱ) can form complexes with Hdbm in different environments. Hdbm reacted with cobalt nitrate to give complex 1 [Co(dbm)₂·2H₂O]. When complex 1 reacted with pyridine， α-stilbazole or 4，4′-bipyridine respectively， complex 2 [Co(DBM)₂Py₂] (Py=pyridine)， 3 [Co(DBM)₂Sbz₂] (Sbz=α-stilbazole) or 4 [Co(DBM)₂BPy]_n was obtained in turn through metathetical reaction. The coordination modes are octahedral polyhedrons. In the crystal structures， the two dbms take the plane position and two other donor molecules take the axial position. CCDC： 196070 for complex 2; 186859 for complex 3.     

Synthesis of Novel Nucleoside Analog （3R）-2,3-Dideoxy-3-（N-hydroxy-N-methylamino）-L-arabinofuranosyl Uracil

The synthesis of novel nucleoside analog (3R)-2,3-dideoxy-3-(N-hydroxy-N-methylamino)-L-arabinofuranosyl uracil was studied. A twelve-step synthetic route, started from L-ascorbic acid, was designed, and the final product was obtained in 20.8% yield.     

CH2XH→CH3X (X＝O, S, Se)异构化的量子拓扑研究

利用从头算和量子拓扑方法讨论了CH₂XH→CH₃X (X＝O, S, Se)异构化过程的反应机理. 着重从电子密度拓扑分析计算了反应进程中的各点, 讨论了反应进程中键的断裂和生成, 上述反应都经历了三元环过渡结构, 找到了这类反应的"能量过渡态"和"结构过渡态", 且结构过渡态均在能量过渡态之后出现. 三元结构过渡态结构出现的范围与反应热成正比.     

邻位吡啶自由基多通道分解反应的动力学和反应机理研究

Utilizing Gaussian94 program package, all species involved in decomposition reactions of o-pyridyl radical were optimized fully at B3LYP/6-311＋＋G^＊＊ level. Intrinsic reaction coordinate calculations were employed to confirm the connections of the transition states and products, and transition states were ascertained by the number of imaginary frequency （0 or 1）. The reaction mechanism was elucidated by the vibrational mode analysis and electronic population analysis, and the reaction rate constants were calculated with transition state theory.     

CBS法合成光学活性二茂铁基醇

以非天然氨基酸合成的手性β-氨基醇(4a～4c)为催化剂，用于不对称硼烷还原反应来合成光学活性的二茂铁基醇(1a～1e)，对映体过量值高达96%。     

高分子光敏剂研究进展

本文综述了近年来国际上关于高分子光敏剂的研究工作进展．     

5-芳酰氨基-2-苯基-2H-1, 2, 4-噻二唑-3-酮的合成

用1-芳酰基-5-苯基-2-硫代双脲与溴进行氧化成环反应制备了九个新的5-芳酰氨基-2-苯基-2H-1, 2, 4-噻二唑-3-酮, 相应的1-芳酰基-5-苯基-2-硫代双脲可以通过苯基脲与酰基异硫氰酸酯加成制得。     

以对-(4-烯丙氧基苯甲酰氧基)苯甲酸对-甲氧基苯酚酯为单体的液晶聚硅氧烷的合成与表征

侧链型液晶聚合物是目前很有兴趣的研究课题之一。在国内,有关的研究报道也逐渐增多,本工作设计并合成了对-(4-烯丙氧基苯甲酰氧基)苯甲酸对-甲氧基苯酚酯单体,其结构式为:     

V(Ⅴ)促进SO_4~(2-)/ZrO_2固体超强酸的制备及催化反应

用低温陈化的方法制得V(Ⅴ)促进型SO42-/ZrO2固体超强酸(SZV),用流动指示剂法测定其酸强度,用IR,XRD和XPS进行结构表征,并将制得的催化剂用于催化乙酸和丙三醇的酯化反应.结果表明,低温陈化样品比常温陈化有更强的酸性和更高的催化活性,IR谱图中S O键的伸缩振动峰显著增强,在600~650℃的焙烧温度下,低温陈化样品的晶体结构为ZrO2四方相,XPS图中Zr3d峰位出现较大的化学位移,表明低温陈化使SZV样品具有较高的酸性.