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991.
A Pd-catalyzed coupling reaction of ArBr/ArCl/ArOTf with sodium thiosulfate takes place in presence of Cs2CO3 at 80 °C. The reaction mixture is directly treated with Zn/HCl to afford aryl thiols in good to excellent yields. 相似文献
992.
Ye Wu Irene Ling Li Ling Fu Jian pang Zhai Shuang Chen Ruan 《Applied Surface Science》2009,255(23):9409-9412
Excimer laser emitting at 248 nm is applied to produce microstructures on the surface of aluminum alloy. The surface morphology shows that hotspots and thermal fluidic structures both come to light. Two possible mechanisms of hotspots formation are proposed: near-field diffraction and interference, and extremely fast rapid thermal annealing. And for the formation of thermal fluidic pattern structure, a thin film model is applied. 相似文献
993.
Zirconium-based metal-organic framework materials (Zr−MOFs) have more practical usage over most conventional benchmark porous materials and even many other MOFs due to the excellent structural stability, rich coordination forms, and various active sites. However, their mass-production and application are restricted by the high-cost raw materials, complex synthesis procedures, harsh reaction conditions, and unexpected environmental impact. Based on the principles of “Green Chemistry”, considerable efforts have been done for breaking through the limitations, and significant progress has been made in the sustainable synthesis of Zr−MOFs over the past decade. In this review, the advancements of green raw materials and green synthesis methods in the synthesis of Zr−MOFs are reviewed, along with the corresponding drawbacks. The challenges and prospects are discussed and outlooked, expecting to provide guidance for the acceleration of the industrialization and commercialization of Zr−MOFs. 相似文献
994.
Fanbo SongJing Zhang Quanbin CuiTing Wang Wenbin ChenLuyuan Li Zhen Xi 《Tetrahedron letters》2012,53(9):1102-1104
Inositol phosphates regulate important biological functions in intracellular signal transduction events. Phosphonates, because of the stability towards the action of phosphatases, were extensively used to replace phosphates. We herein reported the synthesis of inositol phosphonate analogues using myo-inositol as the starting material, and found that two of phosphonate analogues exhibited relative good cytotoxic activity against non-small cell lung cancer (NSCLC) cell line A549. 相似文献
995.
Yumeng Xi Trevor W. Butcher Jing Zhang John F. Hartwig 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(2):786-790
We report the regioselective and enantioselective formal hydroamination of unsymmetrical internal alkenes catalyzed by a copper catalyst ligated by DTBM‐SEGPHOS. The regioselectivity of the reaction is controlled by the electronic effects of ether, ester, and sulfonamide groups in the homoallylic position. The observed selectivity underscores the influence of inductive effects of remote substituents on the selectivity of catalytic processes occurring at hydrocarbyl groups, and the method provides direct access to various 1,3‐aminoalcohol derivatives with high enantioselectivity. 相似文献
996.
Michael Addition Catalyzed by Chiral Secondary Amine Phosphoramide Using Fluorinated Silyl Enol Ethers: Formation of Quaternary Carbon Stereocenters 下载免费PDF全文
Jin‐Sheng Yu Fu‐Min Liao Wei‐Ming Gao Kui Liao Run‐Lin Zuo Prof. Dr. Jian Zhou 《Angewandte Chemie (International ed. in English)》2015,54(25):7381-7385
A chiral secondary amine phosphoramide was developed and identified as a powerful catalyst for the Mukaiyama–Michael addition of fluorinated enol silyl ethers to tetrasubstituted olefins. The resulting products are obtained with high enantioselectivities and contain a quaternary carbon stereocenter bearing either a difluoroalkyl or monofluoroalkyl group. 相似文献
997.
Xi Liu Yi Qin Junlong Zhu Xiaoli Zhao Tanyu Cheng Yanrong Jiang Haitao Sun Lin Xu 《中国化学快报》2021,32(4):1537-1540
A series of triphenylamine (TPA) derivatives with various substituent groups were prepared and showed different absorption and fluorescence characteristics due to the substituent effect. On account of the existence of pyridine units, these TPA derivatives exhibited acid-induced tunable multicolor fluorescence emission including white light emission. In addition, acid-induced fluorescence regulation of these compounds has been also realized in the solid state, which enable them to be successfully constructed the stimuli-responsive fluorescent films and fluorescent inks for inkjet printing. 相似文献
998.
Jinhua Ji Hao Liu Zewei Chen Yajun Fu Prof. Weijun Yang Prof. Shuang-Feng Yin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(43):11102-11109
Metal-organic framework (MOF) is an ideal precursor/template for porous carbon, and its active components are uniformly doped, which can be used in energy storage and catalytic conversion fields. Metal-organic framework PCN-224 with carboxylporphyrin as the ligand was synthesized, and then Zn2+ and Co2+ ions were coordinated in the center of the porphyrin ring by post-modification. Here, PCN-224−ZnCo with different ratios of bimetallic Zn2+/Co2+ ions were used as the precursor, and the metal-nitrogen-carbon(M−N−C) material of PCN-224−ZnCo-950 was obtained by pyrolyzing the precursor at 950 °C in Ar. Because Zn is easy to volatilize at 950 °C, the formed M−N−C materials can reflect different Co contents and different basic site concentrations. The formed material still maintains the original basic framework. With the increase of Zn2+/Co2+ ratio in precursor, the concentration of N-containing alkaline sites in pyrolysis products gradually increase. Compared with the precursor, PCN-224−ZnCo1-950 with Zn2+/Co2+=1 : 1 has greatly improved basicity and suitable acidic/ alkaline site concentration. It can be efficiently used to carbon dioxide absorption and catalyze the cycloaddition of CO2 with epoxide. More importantly, the current method of adjusting the acidic/basic sites in M−N−C materials through volatilization of volatile metals can provide an effective strategy for adjusting the catalysis of MOF derivatives with porphyrin structure. 相似文献
999.
1000.
<正>A novel polyester containing ferrocenyl was prepared by low-temperature interface polycondensation of 1,1'-ferrocenedicarboxylic acid chloride with 4-(4-hydroxyphenyl)-2,3-phthalazin-1-one(DHPZ),which is a twisted non-coplanar heterocyclic bisphenol-like monomer.The newly generated polymer was evaluated based on characterization of its solubility,viscosity measurements,elemental analysis,FTIR spectroscopy,differential scanning calorimetric and thermogravimetric studies. 相似文献