A simple and efficient copper oxide-catalyzed Barbier–Grignard reaction of unactivated aryl or alkyl bromides with ester

An efficient one-pot route to synthesize tertiary alcohol compounds using Barbier–Grignard reaction of unactivated alkyl or aryl bromides with ester in THF at 65 °C catalyzed by CuO has been developed and systematically investigated. A wide range of substituted tertiary alcohol compounds were obtained in good to high yields. The reaction is highly chemoselective. The mechanism involving the leaving group of R²O^-group is discussed.     

One-pot synthesis of peony-like Bi2S3/BiVO4(040) with high photocatalytic activity for glyphosate degradation under visible light irradiation

In this work, samples consisting of BiVO₄ with exposed (040) facets coupled with Bi₂S₃ (Bi₂S₃/BiVO₄) were prepared through a one-pot hydrothermal method, using ethylenediaminetetraacetic acid as directing agent and L-cysteine as sulfur source and soft template. X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy measurements indicated that the Bi₂S₃ content had a significant influence on the growth of (040) and (121) facets as well as on the morphology of the Bi₂S₃/BiVO₄ samples. When the Bi₂S₃ content reached 1 mmol, the Bi₂S₃/BiVO₄ samples exhibited a peony-like morphology. The results of transient photocurrent tests and electrochemical impedance spectroscopy measurements confirmed that a more effective charge separation and a faster interfacial charge transfer occurred in Bi₂S₃/BiVO₄ than BiVO₄. The enhanced photocatalytic activity of the Bi₂S₃/BiVO₄ samples could be attributed to the improved absorption capability in the visible light region and the enhanced electron-hole pair separation efficiency due to the formation of the Bi₂S₃/BiVO₄ heterostructure. In addition, the Bi₂S₃/BiVO₄ samples showed relative stability and reusability. The simple method presented in this work could be used to fabricate composite photocatalysts with high activity for different applications, such as photocatalytic degradation of organic pollutants, photocatalytic splitting of water, and photocatalytic reduction of carbon dioxide.     

聚左旋乳酸/聚消旋乳酸共混物的结晶行为

非晶态聚消旋乳酸(PDLLA)对PLLA的结晶行为有较大的影响。本文利用差示扫描量热仪(DSC)和偏光显微镜(POM)对不同分子量PLLA、PDLLA按不同比例制得的共混物结晶进行了系统研究。结果表明随PDLLA含量的增大PLLA冷结晶温度升高,且越接近熔融温度。PDLLA分子量较小时PLLA球晶特征被明显破坏,PDLLA分子量较大时PLLA更易形保持球晶特征且易形成环带球晶形貌,这与结晶速率与非晶组分的扩散速率匹配程度有关。低分子量的PDLLA使PLLA的最大生长速率对应的温度出现在较低温度。     

CRBN调节剂Avadomide的合成工艺优化

Avadomide是处于Ⅱ期临床阶段用于治疗晚期实体瘤的潜在药物,本文对其合成工艺进行了研究,并对重要中间体的合成工艺进行了优化。以3-硝基邻苯二甲酰亚胺为起始原料,依次经开环、霍夫曼降解、环化、酯的氨解反应、氢氧化钯/碳加氢还原反应得到Avadomide,总收率为46.9%,产物结构经~1H NMR、~(13)C NMR和HRMS表征,纯度经HPLC检测为99.5%。优化后的工艺路线具有反应条件温和、后处理简单、产率高、可操作性强等特点,更适合Avadomide的工业化生产。     

CO加氢制备低碳烯烃Fe基、Co基催化剂研究进展

CO加氢制备低碳烯烃是非石油路线获得烯烃的重要反应,其反应路线有直接法和间接法。直接法制备低碳烯烃具有反应路线短、能源利用率高、经济高效等优势。综述了近年来Fe基催化剂、Co基催化剂在CO直接制备低碳烯烃中的研究进展。分析认为：费托合成过程产物选择性遵循Anderson-Schulz-Flory（ASF）分布规律,助剂和载体的使用一定程度提高Fe基、Co基催化剂的低碳烯烃选择性。     

Fabrication of Boron Nitride Nanosheets by Exfoliation

Nanomaterials with layered structures, with their intriguing properties, are of great research interest nowadays. As one of the primary two‐dimensional nanomaterials, the hexagonal boron nitride nanosheet (BNNS, also called white graphene), which is an analogue of graphene, possesses various attractive properties, such as high intrinsic thermal conductivity, excellent chemical and thermal stability, and electrical insulation properties. After being discovered, it has been one of the most intensively studied two‐dimensional non‐carbon nanomaterials and has been applied in a wide range of applications. To support the exploration of applications of BNNSs, exfoliation, as one of the most promising approaches to realize large‐scale production of BNNSs, has been intensively investigated. In this review, methods to yield BNNSs by exfoliation will be summarized and compared with other potential fabrication methods of BNNSs. In addition, the future prospects of the exfoliation of h‐BN will also be discussed.     

一种卡宾配合物的合成及其在Suzuki反应中的应用

合成了一种N-杂环卡宾的钯配合物,可用于高效地催化芳基溴化物和对甲苯磺酸芳酯对芳基硼酸的Suzuki偶联反应.该反应在二氧六环溶剂中以醋酸钾为助剂、空气氛下80℃即可进行,具有收率高、催化剂容易制备等优点.     

TiO2光催化氧化研究进展

探讨了TiO2光催化氧化技术的原理,其研究现状,以及可能提高TiO2光催化氧化效率的途径。采用参考文献18篇。     

纳米颗粒复合材料增强的葡萄糖生物传感器

二氧化硅和金或铂组成的复合纳米颗粒可以大幅度地提高葡萄糖生物传感器的电流响应,其效果明显优于这三种纳米颗粒单独使用时对葡萄糖生物传感器的增强作用。除了具有吸附浓缩效应,吸附定向和量子尺寸颗粒 应外,复合纳米颗粒比单独一种纳米颗粒更易于形成连续势场,降低电子在电极和固定化酶间的迁移阻力,提高电子迁移率,有效地加速了酶的再生过程,因此复合纳米颗粒显著增强了传感器电流响应。     

TS-1分子筛催化双氧水氧化环己烷(英文)

系统地研究了ＴＳ－１分子筛催化双氧水氧化环己烷的反应。制备了三种ＴＳ－１分子筛,它们具有窄的粒径分布,在６０℃表现出高的活性和选择性。考察了溶剂、催化剂、反应温度、反应时间、ＴＳ－１中Ｔｉ含量及Ｈ２Ｏ７用量对氧化反应的影响。对具有完好晶型的ＴＳ－１分子筛役有必要进行预处理。最佳反应温度为８０～１１０℃,丙酮为最佳溶剂。环己酮的选择性与ＴＳ－１粒子大小有关,而Ｈ２Ｏ２选择性与ＴＳ－１用量无关。实验结果显示．溶剂在反应中间体的形成中起重要作用,Ｔｉ与丙酮配体的过氧配合物具有活化环己烷的活性。关键词 ＴＳ－１ 环己烷 催化氧化 Ｈ２Ｏ２