4′-去甲基表鬼臼毒素与DDQ的反应

4′ 去甲基表鬼臼毒素与 2 ,3 二氯 5,6 二氰对苯醌在醋酸存在下进行反应 .反应温度在室温时可得到邻二酚衍生物 .当反应温度升高到 75℃时 ,则分离到萘衍生物 .本文分析了产物的结构并给出了不同条件下的可能反应机理     

AM1 andab initio studies on the internal reorganization energy of self-exchange electron transfer reactions of several quinone derivatives

The semiempirical AM1 method, ab initio (HF/3-21G, 6-31G, 6-31G(d), 6-31+G(d)) and DFT (B3LYP/6-31G(d), 6-31+G(d)) methods were used to optimize the geometry of DDQ and its anion radical . Nelsen’s model was used to calculate the internal reorganization energy ?i of self-exchange electron transfer (ET) reactions. The calculated l _i results of by AM1 and B3LYP/ 6-31G(d), 6-31+G(d) methods are close to each other and consistent with the reported values; while those from Hartree-Fock methods are too large because of not considering the effect of electron correlation. The structure and ET behavior of couple were studied by AM1 and DFT (B3LYP/6-31G(d), 6-31+ G(d, p)) methods, and those of (n = 1—7) were studied by AM1 method for the first time. The results indicate that the values of the heat of formation of MQ_n increases with the increasing of the length of the isoamylene substituent chains. It also shows that the length of substituent has little effect on the bond lengths, bond angles of ring A, ring B and the dihedral angles of ring B, but it has considerable effect on the dihedral angles between the plane of ring A and oxygen atoms. The calculated l _i results of and (n = 1—7) indicate that not only the changes of high frequency vibrations, corresponding to the changes of bond lengths and bond angles, contribute to l _i of (n = 1—7), but also do those of the low frequency vibrations, corresponding to the changes of dihedral angles of MQ_n and . The contribution from the change of low frequency vibrations between the plane of ring A and oxygen atoms to the l _i values of (n = 1—7) is greater than 1.60 kJ/mol; in addition, the contribution from the changes of the low frequency vibrations of the isoamylene substituent to the l _i values of and is about 2 kJ/mol.     

4＇－去甲基表鬼臼毒素和DDQ在醋酸或苯中的氧化反应

在醋酸或苯溶液中，用ＤＤＱ氧化４＇－去甲基表鬼臼毒素得到一种芳基萘化合物，本文给出了可能的反应机理和光谱数据．     

Unexpected and Intriguing Reactivity of Imino Compounds

We have recently discovered a tandem N-alkylation-C-allylation reaction of α-imino esters with organoaluminum reagents and allyltributyltin. In this reaction, iminium salts were readily prepared in situ by the oxidation of aluminum enolates, and the subsequent nucleophilic addition proceeded smoothly to afford N-alkylation-C-allylation products in good yields. During these studies, we focused on the generation of iminium species 2 by oxidizing a readily accessible and stable enol derivative with oxidants. A convenient method has been found for the generation of α-alkoxycarbonyl iminium salts 2 from ketene silyl acetals and the subsequent reaction with nucleophiles.     

一种有效评估桥接故障的IDDQ可测试性分析算法

鉴于传统的可测试性分析算法不能处理重汇聚扇出问题,该文提出了一种有效的评估电路桥接故障可测试性的IDDQ可测试性分析算法.这种算法是基于给电路中每个门施加基本矢量集的概率进行的.开始在原始输入端采用单值标记,通过电路分级和从原始输入端传播标记集可识别重汇聚扇出门,然后采用反向蕴含过程计算重汇聚门基本矢量的概率值,进行重汇聚扇出点的评价.实验结果表明这种算法可获得较精确的可测试性分析结果.     

DDQ钢连铸坯洁净度

采用金相观测、扫描电镜、电子探针等方法,研究了某钢厂DDQ钢连铸坯的洁净度,对铸坯中夹杂物的数量、粒径、分布、形貌及组成等进行了讨论。研究结果表明,该DDQ钢连铸坯中w(O)<14×10-6、w(N)=18×10-6,P、S含量低,没有进行钙处理及真空处理;夹杂物大部分在4μm以下,数量少且分布均匀;夹杂物纯Al2O3居多,有MnS夹杂及以Al2O3为中心的外面是MnS的复合夹杂。