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Alstonerine属于单萜吲哚生物碱,除其结构很有特征外,还报道对两株人肺癌细胞具有细胞毒性,因此,它自然就成为合成化学的重要目标.已经有多种合成策略用于构建这个结构体系:包括Pictet-Spengler反应和Dieckmann缩合反应、烯烃复分解关环反应、膦配体催化的[4+2]关环/Friedel-Craft环化、氮杂-Diels-Alder反应/分子内Heck反应、Pauson-Khand反应等.本工作根据构建环系的不同反应系统总结了Alstonerine的合成方法.大部分合成反应步骤较多,适合工业生产的有效合成方法还有待于进一步探索. 相似文献
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合成子和合成等效剂是有机合成的发展过程中提出的新概念。深刻了解这一概念及其有关知识对于提高有机合成设计水平和发展有机合成设计技巧,尤其在运用计算机进行有机合成路线的择优中,都具有一定的意义。本文将分别就合成子、合成等效剂以及合成子的类型转换作一介绍。 相似文献
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具有八面体结构单元的类沸石锆硅矿物Umbite的合成研究 总被引:1,自引:0,他引:1
在K2O-KF-ZrO2-SiO2-H2O体系中,研究了水热合成方法制备类沸石矿物Umbite的合成规律.考察了无机盐种类、有机添加物种类、碱源等对合成Umbite合成的影响.用XRD、SEM、FT-IR、化学分析等对合成样品加以表征.实验结果表明可合成Umbite的原料配比为K2O/SiO2/ZrO2/KF/TMABr/H2O=(1.0-3.0)∶1∶(0.01-0.2)∶(0.3-3.0)∶(0.3-1.2)∶36.8;有机添加物在Umbite合成中仅仅影响了晶化速率;受四面体与八面体交替排列的结构限制,产物中Si/Zr可调性较小. 相似文献
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A two-minute microwave irradiation allowed the synthesis of several 2-aminothiophene-3-carboxylic acid derivatives. Their efficient transformation to thieno[2,3-d]pyrimidin-4-one and the corresponding 4-chloro derivative is also reported under microwave irradiation. 相似文献
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微波在有机合成化学中的应用及进展 总被引:31,自引:4,他引:27
简述了微波有机合成的机理和特点,介绍了近年来微波辐射技术在有机合成中的应用,展望了微波促进有机合成化学的发展方向。参考文献30篇。 相似文献
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Despite the advances of solid phase peptide synthesis (SPPS) the synthesis of long peptides is still challenging. Microwave irradiation and conventional heating are considered to improve the efficiency of SPPS. It has been shown that conventional heating and heating by microwave irradiation improves the efficiency of solid phase synthesis of peptides that are prone to aggregation as compared to the synthesis at room temperature. In this Letter, the influence of elevated temperature and microwave irradiation on the homogeneity of the synthesis product of a 58-mer peptide affibody has been compared. A detailed analysis by high resolution HPLC and LC-MS mass spectrometry using a high-mass resolution Orbitrap Exactive mass spectrometer was performed. This study revealed that neither thermal heating nor microwave heating improves the yield and purity of the crude product as compared to the synthesis at room temperature. In contrast, the formation of undesirable side products rather increased by microwave irradiation. These results indicate that neither heating nor microwave enhancement of solid phase synthesis does allow a significant improvement of peptide sequences with a low aggregation potential. 相似文献
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Jhung SH Jin T Hwang YK Chang JS 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(16):4410-4417
Microporous materials, such as silicalite-1 and VSB-5 molecular sieves, have been synthesized by both microwave irradiation (MW) and conventional electric heating (CE). The accelerated syntheses by microwave irradiation can be quantitatively investigated by various heating modes conducted in two steps such as MW-MW, MW-CE, CE-MW, and CE-CE (in the order of nucleation-crystal growth). In the case of synthesis by MW-CE or CE-MW, the heating modes were changed for the second step just after the appearance of X-ray diffraction peaks in the first step. We have quantitatively demonstrated that the microwave irradiation accelerates not only the nucleation but also crystal growth. However, the contribution to decrease the synthesis time by microwave irradiation is larger in the nucleation stage than in the step of crystal growth. The crystal size increases in the order of MW-MW相似文献
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Maria Antonia Tnase Maria Marinescu Petruta Oancea Adina Rducan Catalin Ionut Mihaescu Elvira Alexandrescu Cristina Lavinia Nistor Luiza-Izabela Jinga Lia Mara Diu Cristian Petcu Ludmila Otilia Cinteza 《Molecules (Basel, Switzerland)》2021,26(7)
In the present work, the properties of ZnO nanoparticles obtained using an eco-friendly synthesis (biomediated methods in microwave irradiation) were studied. Saponaria officinalis extracts were used as both reducing and capping agents in the green nanochemistry synthesis of ZnO. Inorganic zinc oxide nanopowders were successfully prepared by a modified hydrothermal method and plant extract-mediated method. The influence of microwave irradiation was studied in both cases. The size, composition, crystallinity and morphology of inorganic nanoparticles (NPs) were investigated using dynamic light scattering (DLS), powder X-ray diffraction (XRD), SEM-EDX microscopy. Tunings of the nanochemistry reaction conditions (Zn precursor, structuring agent), ZnO NPs with various shapes were obtained, from quasi-spherical to flower-like. The optical properties and photocatalytic activity (degradation of methylene blue as model compound) were also investigated. ZnO nanopowders’ antibacterial activity was tested against Gram-positive and Gram-negative bacterial strains to evidence the influence of the vegetal extract-mediated synthesis on the biological activity. 相似文献
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Navjeet Kaur 《合成通讯》2013,43(4):432-457
The development of new strategies for the synthesis of small-sized heterocycles hasremained a highly attractive but challenging proposition. An overview of the application of microwave irradiation in the synthesis of nitrogen-containing five-membered heterocyclic compounds is presented, focusing on the developments in the past 5–10 years. This contribution covers the literature concerning the total synthesis of N-heterocycles. 相似文献
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Navjeet Kaur 《合成通讯》2013,43(7):789-823
The development of new strategies for the synthesis of small-sized heterocycles has remained a highly attractive but challenging proposition. An overview of the application of microwave irradiation in nitrogen-containing fused five-membered heterocyclic compounds synthesis is presented, focusing on the developments in the past 5–10 years. This contribution covers the literature concerning the total synthesis of fused N-heterocycles. 相似文献
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Navjeet Kaur 《合成通讯》2013,43(1):35-69
The development of new strategies for synthesis of polycyclic heterocycles has remained a highly attractive but challenging proposition. An overview of the application of microwave irradiation in nitrogen-containing six-membered polycyclic heterocyclic compounds synthesis is presented, focusing on the developments in the past 5–10 years. This contribution covers the literature concerning the total synthesis of N-heterocycles. 相似文献