相转移催化法合成取代苯甲酸葡萄糖酯

在相转移催化剂四丁基碘化铵的作用下．溴代乙酰基葡萄糖与取代苯甲酸反应合成了6个取代苯甲酸葡萄糖酯．所合成的糖酯的结构经IR、^1HNMR、元素分析确证。通过对糖酯化合物的^1HNMR图谱中糖环C1位质子的化学位移及偶合常数．并结合红外图谱中糖环C1H的弯曲振动吸收,确证糖酯化合物均为β型异构体。     

咔唑类生物碱玫瑰树碱的合成研究进展

玫瑰树碱是从常绿植物椭圆玫瑰树中分离得到的具有平面结构的咔唑类生物碱,对DNA中的碱基对有特异性作用,该化合物及其水溶性衍生物具有抗肿瘤和抗HIV活性,且结构相对简单,因此,研究者开发了多种合成策略。本文按照构建环系的不同方式,综述玫瑰树碱化学合成方法,其中苯环吡咯环+吡啶环(AB+D环)构建苯环(C环)的合成策略,合成步骤相对较少,吲哚和吡啶衍生物原料较易得到,该策略具有更广阔的发展空间。     

有机小分子不对称催化构建氧化吲哚C(3)位螺环化合物的研究进展

螺环氧化吲哚结构是很多药理活性分子的核心骨架,其结构复杂且在合成过程中立体选择性难以控制,因此含有该骨架的化合物是药物和有机化学家关注的热点。按吲哚C(3)位上构建的三元螺环、四元螺环、五元螺环和六元螺环进行分类,介绍近5年来有机小分子不对称催化构建螺环氧化吲哚化合物的研究进展,以期为该类化合物的合成提供参考价值。     

甘氨酰谷氨酰胺有关物质的结构鉴定与合成

在甘氨酰谷氨酰胺质量研究中,通过高温破坏,分析了3个主要的降解杂质,其中一个通过LC-MS分析,推测其结构为了环-(甘氨酰-谷氨酸)。以甘氨酰谷氨酰胺为原料,经过酯化、氨解成环得到了有关物质A环-(甘氨酰-谷氨酰胺),再经碱性水解得到有关物质B环-(甘氨酰-谷氨酸)。还以谷氨酸为原料,合成了有关物质C甘氨酰谷氨酸。这些杂质结构经1H NMR、13C NMR、MS和IR确证。     

咪唑大环分子的合成及应用研究

核苷酸,ATP及GTP是生命活动密切相关的物质,咪唑大环分子中具有较大的空腔且其中的C(2)-H能够参与形成较强的氢键,进而能够进行修饰及结构优化。文章在之前已有的科研报道背景下,对咪唑大环分子的合成进行了进一步的研究。     

轴手性酰基硫脲催化合成吡唑啉酮衍生物

吡唑啉酮环化合物因具有生物药理活性等多种特性和用途,被认为是极具价值的结构基元之一,吡唑环上易形成氢键等特性使得药物分子中的吡唑啉酮结构能够发挥生理活性.合成了多种以3,3'-二羧酸-1,1'-联萘酚为手性骨架、结构上下对称的新型多活性中心C2轴手性氢键型双酰基硫脲催化剂,将其用于催化合成吡唑啉酮衍生物.实验结果表明:...     

马来海松香酸封端的聚酰亚胺低聚物的合成及热性能

以马来海松香酸作为封端剂合成了一系列新型聚酰亚胺(PI)低聚物,并对产物进行了结构表征.研究发现,该类聚合物显示了较好的热稳定性,其中PI-3的5%热失重温度达到340C,在TDG曲线上显示了两个链段分解过程,分别对应于松香脂环结构和酰亚胺环结构的分解.     

含噻唑环核N-硝基亚胺基咪唑烷类化合物的合成及生物活性研究

以氯噻啉为先导,利用类同合成方法,保留氯噻啉结构中噻唑环2-位氯原子,通过变换噻唑环4-位取代基,设计合成了8个氯噻啉类似物。所有化合物的结构均经~1H NMR、~(13)C NMR、质谱及元素分析等确认。初步生物活性测试结果表明:该类化合物具有一定的杀虫活性。在200μg/m L的浓度下,化合物8a和8g对桃蚜(Myzus persicae)致死率达70%。     

C(2)位螺环氧化吲哚化合物合成研究进展

C(2)位螺环氧化吲哚化合物存在于许多天然生物碱和生物活性物质中,具有多种生物活性,由于结构新颖、独特且合成难度较大,因此该类化合物的合成引起了有机化学家和药物化学家的关注。在对近几年来氧化吲哚C(2)位螺环化合物合成方法调研的基础上,分别以过渡金属催化、高价碘试剂介导催化、有机催化、酸碱介导催化重排、光催化和其他催化等不同合成方法进行分类介绍该类化合物的研究进展,以期为该类化合物的后续研究提供参考。     

新型香料环丙香豆素的合成及加香应用研究

以香豆素为原料通过Corey-Chaykovsky反应一步合成了环丙香豆素。通过~1H NMR、~(13)C NMR、HRMS对产物进行了表征,确认了化合物的结构,并对反应条件进行了优化。进一步对产物的香气进行了评价,在卷烟中添加环丙香豆素能明显改善烟气及香气品质。     

国内C9石油树脂生产现状与发展研究

介绍了C9石油树脂的原料组成及C9石油树脂合成机理。对C9石油树脂的合成工艺进行了介绍,阐述了合成工艺的选择原则并对几种C9石油树脂的合成工艺进行了比较分析。重点介绍了C9石油树脂合成工艺的发展状况,指出了C9石油树脂加氢技术研发要解决的关键技术及发展方向。     

C306型甲醇合成催化剂在我厂的应用

介绍了C306型甲醇合成催化剂在大庆油田甲醇厂的实际应用情况。阐述了C306型催化剂的特点,总结了C306型催化剂在生产操作及管理中的使用经验。     

Synthesis and Characterization of Ceramic Membranes (W‐Type Zeolite Membranes)

In this article, effects of synthesis parameters (synthesis temperature, synthesis time, and number of layers) on W‐type zeolite membranes synthesized over flat SUS supports for O₂/SF₆ gas separation were experimentally investigated. Experiments were carried out at these levels of synthesis temperature: 165°C, 185°C, and 200°C; synthesis time: 6, 12, and 18 h and number of layers: 1 and 2. Permeation measurements, XRD and SEM analysis were used for characterization of the synthesized membranes. The results showed that increasing synthesis temperature from 165°C up to 185°C increases separation factor of O₂/SF₆, however, further increasing decreases the separation performance. The same trend was observed for synthesis time for the single layer synthesized zeolite W membrane, although for the double layer synthesized zeolite W membrane, separation factor increased with increasing synthesis time. Repetition of layering has a net positive effect on separation factor of O₂/SF₆, and negative effect on permeation flux through the membranes. This behavior was attributed to the dual effect of synthesis temperature and synthesis time on selectivity. More zeolite crystals are deposited and larger crystals are formed at higher synthesis temperatures and longer synthesis times. Well W‐type zeolite membrane was synthesized at 185°C for 18 h with two repeating layers with a high separation factor of 20.1.     

丙烯酸高级酯的微波合成与结构表征

以丙烯酸、十二醇、十四醇、十六醇、十八醇为原料,采用微波辅助合成技术分别制备了丙烯酸十二酯、丙烯酸十四酯、丙烯酸十六酯和丙烯酸十八酯。考察了微波功率、辐射时间和原料配比等反应条件对不同长链酯酯化产率的影响,并对它们的物理性质、元素组成和分子结构进行了测定与表征。结果表明,微波辅助合成技术能高效、快速地合成丙烯酸高级酯,但各高级酯的最佳微波酯化条件明显不相同,随着高级酯碳链的增长,微波功率、辐射时间和酸醇摩尔比增大,在优化的微波合成条件下,反应速率可提高20倍以上,酯产率≥96%,且所得产物的物理性质、分子结构与传统方法加热制备的产物无明显差异。     

Rapid Crystallization of Silicalite Nanocrystals in a Capillary Microreactor

Silicalite nanocrystals were synthesized in a pressurized capillary microreactor at 150 °C within 11 min with synthesis solutions aged at 80 or 100 °C for 1–6 h. The effects of aging of the synthesis solution and the reaction pressure were examined. The resulting products were characterized by XRD, DLS, TEM, FT‐IR and TG‐DSC. Aging of the synthesis solution played an important role in shortening the crystallization time of the silicalites. The synthesis pressure should be higher than the saturation vapor pressure of water at 150 °C (～0.5 MPa) and silicalite nanocrystals with crystallinities of 70 % and 100 % could be produced from the synthesis solution aged at 100 °C for 2 h with residence times of 11 min at 0.7 MPa and 1 MPa, respectively. The mean particle sizes of these two samples were 102.2 nm and 166.4 nm, respectively. Thus, the crystallization time of the silicalite nanocrystals is shown to be significantly reduced in the capillary microreactor compared to a traditional batch system.     

Hydrogenation processes in the synthesis of perfumery ingredients

Homogeneous catalytic hydrogenation has played an important role in the development of modern organic synthesis. Indeed, the discovery of highly regio- and stereoselective catalysts for C=C and C=O bonds reductions has allowed the efficient synthesis of optically active compounds. As the fragrance industry has turned to synthetic ingredients to fulfill the need for novel, cost-effective, and environment-friendly products, the use of catalytic processes are more and more in demand. In this Account, we thus highlight the application of catalytic hydrogenation in the synthesis of fragrance ingredients.     

一碳化工产品及其发展方向

一碳化工是替代石油合成路线制备基本有机化工原料、燃料和其他重要化学品的最重要的最有发展前景的途径.本文综合讨论了以含一个碳原子化合物为原料合成化学品和新材料的国内外研究与开发的进展,包括已工业化的技术.同时也对一碳化工产品发展方向和与一碳化合物相关的能源技术产品、环境保护技术产品及低品位一碳化合物资源化技术作了较全面的分析.     

Effects of renal factors on in vitro hepatic cholesterol synthesis in the rat

Two products derived from rat renal tissue have been shown to affect in vitro hepatic cholesterol synthesis. A premevalonate inhibitor of hepatic cholesterol synthesis is associated with the membranes of the renal endoplasmic reticulum. It is stable at −75 C and at 4 C but is heat labile. A pre-mevalonate stimulator of in vitro hepatic cholesterol synthesis is located within renal lysosomes and can be prepared in a nonsedimentable form by extraction with hypotonic buffer. While it is stable at −75 C, it loses activity at 4 C. Both of these products appear to have a molecular weight in excess of 150,000 as determined by gel filtration. Deceased.     

基于2-溴芳基烷基酮的C—N键构建反应

C—N键的构建反应对于药物开发,天然产物合成,以及含氮化合物的代谢等都具有重要意义。本文结合作者的研究,主要介绍基于2-溴芳基烷基酮的C—N键构建反应及其在药物合成中的应用。     

Introducing trace Co to molybdenum carbide catalyst for efficient ammonia synthesis

Development of the cost-effective catalysts with excellent catalytic performance is highly demanded for ammonia synthesis, and the strong adsorption of ammonia greatly hinders the design of cost-effective and high-performance ammonia synthesis catalysts. Herein, we report that the addition of a small amount of Co species (0.1 wt%) into Mo₂C catalyst, which can provide electrons to Mo₂C, not only leads to improvement of the adsorption and migration of hydrogen, but also facilitates the adsorption and desorption of ammonia. Consequently, Mo₂C catalyst with 0.1 wt%Co offers a 40% higher ammonia synthesis activity and a lower negative reaction order with respect to NH₃ in comparison to Mo₂C. This work stresses the importance of the minor components in improving the ammonia synthesis activity by accelerating the migration of reactants over the catalyst surface and the escape of products from the catalyst.