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981.
Two syntheses for 4-nitrocyclohexanol and 4-nitrocyclohexanamine are presented. Both conveniently start from commercially available 4-aminocyclohexanol. 相似文献
982.
Jiawei Zhang Yiliu Liu Bin Yuan Prof. Zhiqiang Wang Prof. Monika Schönhoff Prof. Xi Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(47):14968-14973
Stable multilayer films with cucurbit[8]uril have been fabricated on the basis of the alternating layer‐by‐layer assembly of a novel side‐chain pseudopolyrotaxane and a photoreactive polyanion. The as‐prepared multilayer films exhibit good properties as surface‐imprinted multilayers, because cucurbit[8]uril molecules that are locked inside the multilayers can act as nanocontainers with specific binding to certain guest molecules, and the loading and release of the guest is redox‐controllable and reversible. 相似文献
983.
K. C. Swallow K. Taghizadeh S. Weakland E. F. Plummer W. F. Busby Jr A. L. Lafleur 《International journal of environmental analytical chemistry》2013,93(2-4):113-122
Abstract We have studied the photooxidation of selected polycyclic aromatic hydrocarbons (PAH) in the presence of Ti(IV)oxide in a mixed solvent system consisting of N-methylpyrrolidinone (NMP) and water. Reaction rates for the photooxidation of acenaphthylene and pyrene were investigated by monitoring the disappearance of the PAH substrate from the reaction mixture as a function of time. For both compounds plots of In Co/Ct, as a function of time yielded straight lines, indicating first order kinetics with respect to the substrate. With an initial acenaphthylene concentration of 1.0 gL?1 the first order reaction rate constant was 0.19 hr?1 and the half life was 3.7 hr. With an initial pyrene concentration of 0.2 gL?1 the first order reaction rate constant was 0.0285 hr?1 and the half life was 24 hr. The photoproducts were characterized by high performance liquid chromatography with diode-array detection (HPLC/DAD) and by liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (APCI/LC-MS). Although a number of simple oxidation products were identified the bulk of the photoproducts consisted of the parent PAH substituted with one or more solvent (NMP) molecules. The product mixtures from the photooxidation of the non-mutagens acenaphthylene and pyrene were found to be also non-mutagenic in our Salmonella typhimurium forward mutation assay. 相似文献
984.
In an attempt to generate antibodies for the development of an immunoanalysis method for potassium and caesium ions, new 1,3-alternate calix[4]arenes-crown-5 and -6 bearing either carboxylic or hydroxyl functions were synthesized in good yields. Their complexation properties towards potassium and caesium ions were investigated using 1H NMR spectroscopy and the usual properties proved to be preserved in the presence of the anchoring arms. 相似文献
985.
986.
Kyoichi Hanada Juntaro Nogami Prof. Dr. Kazunori Miyamoto Norihiko Hayase Dr. Yuki Nagashima Yusuke Tanaka Dr. Atsuya Muranaka Prof. Dr. Masanobu Uchiyama Prof. Dr. Ken Tanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(36):9313-9319
The enantioselective synthesis of aza[6] and [7]helicene-like molecules have been achieved by the cationic rhodium(I)/axially chiral biaryl bisphosphine complex-catalyzed intramolecular [2+2+2] cycloaddition of cyanodiynes. This protocol was successfully applied to the diastereo- and enantioselective synthesis of an S-shaped double aza[6]helicene-like molecule with a high ee value of 89 %. Although no epimerization and racemization were observed in the double carbo[6]helicene-like molecule at 80 °C, epimerization and racemization of the double aza[6]helicene-like molecule proceeded at 80 °C. This double aza[6]helicene-like molecule showed good fluorescent quantum yields and chiroptical responses under both neutral and acidic conditions. 相似文献
987.
Wang Kang Xingqiong Du Lanzhi Wang Lijuan HU Yuhuan Dong Yanqing Bian Yuan Li 《中国化学》2013,31(10):1305-1314
Our studies examined the structural features responsible for the antifungal activity of 2-ethoxycarbonyl-1,5- benzothiazepine (7a). Three series of 1,5-benzothiazepine derivatives were synthesized and screened for their antifungal activity. The results suggested that the ethoxycarbonyl group at the 2 position and the imine moiety on the seven-membered ring are essential for activity. The most potent of the synthesized analogues (7a, 7b) were further studied by evaluating their cytotoxicity and mode of action (for 7a). The results showed that compounds 7a and 7b were relatively safe for BV2 cells, but compound 7a interfered with Cryptococcus neoformans cell wall integrity by increasing the chitinase activity. Therefore, compound 7a was considered safe as an antifungal agent for animal cells. 相似文献
988.
Two new guaianolide-type sesquiterpenoids,4β,9β-dihydroxy-1α,5α-H-guaia-6,10(14)-dien(1) and 4β,9β,10α-trihydroxy-1α,5α-H-guaia-6-en(2),along with four known sesquiterpenoids(3a,3b,4 and 5),were isolated from Kadsura interior.Their structures and configurations were elucidated by spectroscopic methods including 2D-NMR and HR-MS techniques.Compounds 3a and 3b were obtained as a pair of enantiomers,and their structure and absolute configuration were established from their extensive NMR spectra and by single-crystal X-ray analysis. 相似文献
989.
990.
Hui Qiang Tao Chen Zhuo Wang Wenqian Li Yunzhe Guo Jie Yang Xueshun Jia Hui Yang Weibo Hu Ke Wen 《中国化学快报》2021,31(12):3225-3229
The development of heterogeneous catalysts with substrate shape, size or electronic constitution selectivity is a huge challenge in photocatalysis. Reported herein is a host-guest interaction strategy to endow photocatalysts with special selectivity. By adjusting the precursors, conjugated macrocycle polymers (CMPs) with pillar[5]arene struts (CMP-1 and CMP-2) and a corresponding non-pillar[5]arene-contained conjugated organic polymer (COP-1) were prepared and the photocatalytic activities toward sulfide derivatives were investigated. The sulfides showed similar conversions when COP-1 was used as a photocatalyst, but exhibited significant differences when it turned to the CMPs. Remarkably, the conversion yield of S-1 achieved near 18 folds over the one of S-2 when CMP-2 was used as a catalyst. Mechanism studies confirmed that the “host-guest” effect of pillar[5]arene struts in CMPs was the main cause of the difference. The present work establishes CMPs as novel heterogeneous photocatalysts with substrate selectivity, and such a method will inspire the researchers concerning preparation of heterogeneous catalysts with excellent selectivity. 相似文献