Carbonylative Stille coupling reactions of benzyl chlorides with allyltributylstannane catalyzed by palladium nanoparticles

The carbonylative Stille coupling reaction of benzyl chlorides with allyltributylstannane was successfully conducted by using palladium nanoparticles as the catalyst under phosphine ligand-free conditions. The corresponding α,β-unsaturated ketone products were obtained in good to excellent yields.     

氮杂环卡宾-钯配合物催化Buchwald-Hartwig偶联反应最新研究进展*

钯催化的Buchwald-Hartwig偶联反应是用于构建C-N键非常直接有效的方法。氮杂环卡宾-钯配合物具有性能稳定、催化活性高等优点,是Buchwald-Hartwig偶联反应的高效催化剂。对这一领域近3年的研究进展作简要介绍。     

烧蚀模式激光推进研究现状

在对国内外文献综合调研的基础上,总结给出了烧蚀模式激光推进的研究现状.通过对各个国家研究成果的对比分析,为我国烧蚀模式激光推进研究提供了一些有参考价值的信息.     

室温下钯催化生成联苯的合成方法

在催化量级的二价钯和氧化剂的作用下,苯直接经碳氢键活化在酸性体系中室温下氧化偶联生成联苯。通过对各种催化剂、氧化剂、酸等因素对联苯产物生成的影响的考察,醋酸钯/过硫酸钾/三氟乙酸体系确定为最有效的反应体系,联苯收率在24 h内可达24%,转化数TON值为6.0。     

Calculating physical properties of organic compounds for environmental modeling from molecular structure

Mathematical models for predicting the transport and fate of pollutants in the environment require reactivity parameter values – that is the value of the physical and chemical constants that govern reactivity. Although empirical structure–activity relationships have been developed that allow estimation of some constants, such relationships are generally valid only within limited families of chemicals. The computer program, SPARC, uses computational algorithms based on fundamental chemical structure theory to estimate a large number of chemical reactivity parameters and physical properties for a wide range of organic molecules strictly from molecular structure. Resonance models were developed and calibrated using measured light absorption spectra, whereas electrostatic interaction models were developed using measured ionization pK_as in water. Solvation models (i.e., dispersion, induction, H-bonding, etc.) have been developed using various measured physical properties data. At the present time, SPARC’s physical property models can predict vapor pressure and heat of vaporization (as a function of temperature), boiling point (as a function of pressure), diffusion coefficient (as a function of pressure and temperature), activity coefficient, solubility, partition coefficient and chromatographic retention time as a function of solvent and temperature. This prediction capability crosses chemical family boundaries to cover a broad range of organic compounds.     

迭代Suzuki偶联反应合成全氟环丁基芳基醚齐聚物的研究

对迭代Suzuki偶联反应合成全氟环丁基芳基醚齐聚物的方法进行了研究, 并合成了全氟环丁基芳基醚齐聚物. 首先从对溴苯酚出发, 合成了含有一个全氟环丁基芳基醚结构单元的中间体3. 芳基硼酸与中间体3进行Suzuki偶联反应, 得到了含有一个全氟环丁基芳基醚结构单元的硼酸. 重复与中间体3进行Suzuki偶联反应, 从而合成了全氟环丁基芳基醚二聚体和三聚体. 最后通过热环化二聚反应合成了全氟环丁基芳基醚三聚体、五聚体和七聚体.     

Expedient BINOL derivative arylations

A dramatic improvement of our previous methodology based on a Suzuki–Miyaura cross-coupling to access 3,3′-disubstituted H₈-BINOLs using microwave heating is reported herein. These new conditions represent a large gain in term of atom-economy, reaction time, catalyst loading, and excess of reagents employed.     

Oxidative Coupling of 4α,9-Diaza-1,2,4α,9α-tetrahydrofluorenes. 5. Reaction with o-Aminophenol and o-Aminothiophenol

Oxidative coupling of 4,9-diaza-1,2,4,9-tetrahydro-9H-fluorenes with o-aminophenol and o-aminothiophenol in the presence of MnO₂ gives o-hydroxyphenyl- and o-mercaptophenylquinonediimines, cyclization of which gives derivatives of phenoxazine and phenothiazine.     

基于波动模态耦合的铝电解槽磁流体稳定性傅立叶级数法分析

铝电解槽内磁流体稳定性对铝电解生产有重要影响。本文结合铝电解槽实体仿真的电磁场计算结果,应用傅立叶级数法对槽内磁流体波动稳定性进行数值计算,并对波动的模态耦合问题进行了重点分析。在此基础上,本文以某320kA铝电解槽为研究载体分析了槽长宽比设计对磁流体稳定性的影响,结果表明:波动的不稳定分量集中分布在频谱图中重力波模态密集的低频区域;不考虑母线对体系的影响,增大槽的长宽比,有利于提高磁流体的稳定性。     

可列值随机变量序列的一个小偏差定理

本文得到了可列值随机变量序列的用不等式表示的强极限定理,即小偏差定理,包含了［１］的结果．［１］中研究的是相对于齐次Ｍａｒｋｏｖ 链的偏差,而本文允许非齐次的情形．