排序方式: 共有94条查询结果,搜索用时 15 毫秒
51.
Yubo Pang Gengtu Liu Congcong Huang Prof. Dr. Xiang-Ai Yuan Prof. Dr. Weipeng Li Prof. Dr. Jin Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(31):12889-12894
We have developed a general and site-predictable manganese-catalyzed hydroarylation of internal alkynes in the presence of water, under an air atmosphere without the involvement of ligand. The unique catalytic feature of this reaction is highlighted by comparison with other widely used transition metal catalysts including palladium, rhodium, nickel, or copper. The simple operation, high efficiency and excellent functional group compatibility make this protocol practical for more than 90 structurally diverse internal alkynes, overcoming the influence of both electronic and steric effect of alkynes. Its exclusive regio- and chemoselectivity originates from the unique reactivity of the manganese-based catalyst towards an inherent double controlled strategy of sterically hindered propargyl alcohols without the installing of external directing groups. Its synthetic robustness and practicality have been illustrated by the concise synthesis of bervastatin, a hypolipidemic drug, and late-stage modification of complex alkynes with precise regioselectivity. 相似文献
52.
为避免物理交联明胶基水凝胶的热不稳定性,以及化学方法交联明胶基水凝胶存在的毒性,本文采用丙烯酰化的方法将甲基丙烯酸酐(MA)与明胶反应,在明胶分子链上引入双键结构,并且实现了紫外光照射引发甲基丙烯酰胺基明胶(GelMA)与聚乙二醇双丙烯酸酯(PEGDA)共聚交联制备水凝胶。研究了不同的MA加入量对明胶修饰度的影响,并对GelMA/PEGDA交联水凝胶理化性质进行了测试和分析。结果表明:体系中PEGDA含量增加,能释放更多的自由基,增加交联反应的活性和程度,使水凝胶形成更加致密的三维网络结构。并且GelMA/PEGDA交联水凝胶在37℃比GelMA交联水凝胶更加稳定。GelMA/PEGDA交联水凝胶将来有望成为组织工程的支架材料。 相似文献
53.
We report supramolecular AND logic gates based on host-guest complexation between acid-labile acyclic cucurbit[n]uril(CB[n]) molecular container and Na Cl O-responsive dye. Supramolecular AND logic gate is turned on due to acid-triggered degradation of molecular container and the release of the dye, followed by Na Cl O-induced fluorescence “switch on” effect of the dye. The reason for AND molecular logic gate is discovered to be the combination of oxidation inhibition and fluorescence “switch of... 相似文献
54.
Liu Kai Li Tingrui Liu Duan-Yang Li Weipeng Han Jian Zhu Chengjian Xie Jin 《中国科学:化学(英文版)》2021,64(11):1958-1963
Science China Chemistry - We report an unprecedented C–H bond functionalization of cyclopropenes enabled by dinuclear gold catalysis. Highly selective C–H allylation, alkynylation and... 相似文献
55.
In this paper, we investigate the space-time regularity of solutions to (1) the three dimensional incompressible Navier–Stokes equations for initial data \(u_{0}=(u_{0}^{h},u_{0}^{3}) \in \dot{B}_{p,r}^{ \frac{3}{p}-1} (\mathbb{R}^{3})\) with large initial vertical velocity component; and (2) the three dimensional incompressible magneto-hydrodynamic equations for initial datum \(u_{0}=(u_{0}^{h},u _{0}^{3})\in \dot{B}_{p,r}^{\frac{3}{p}-1} (\mathbb{R}^{3})\) with large initial vertical velocity component and \(b_{0}=(b_{0}^{h},b_{0}^{3}) \in \dot{B}_{p,r}^{\frac{3}{p}-1} (\mathbb{R}^{3})\) with large initial vertical magnetic field component.
相似文献56.
57.
Back Cover: Cobalt‐Catalyzed C(sp2)−H Methylation by using Dicumyl Peroxide as both the Methylating Reagent and Hydrogen Acceptor (Chem. Eur. J. 35/2016)
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Qun Li Yanrong Li Weipeng Hu Renjian Hu Prof. Guigen Li Hongjian Lu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12568-12568
58.
59.
College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310032, China MgI2(Et2O)n promoted aldol condensation of various aldehydes with acyldiazomethane was described in the presence of DIPEA in good to excellent yields under mild conditions with high chemoselectivity. 相似文献
60.