79865-89-7Relevant academic research and scientific papers
A highly efficient Co-based catalyst fabricated by coordination-assisted impregnation strategy towards tandem catalytic functionalization of nitroarenes with various alcohols
Li, Guangming,Li, Jingfang,Li, Weizuo,Li, Xuewei,Li, Zhibin,Mao, Guijie,She, Wei,Wang, Jing
, p. 462 - 474 (2021/11/11)
A well-defined hexamethylenetetramine (abbreviated as HMTA) based two-dimensional (2D) MOFs metalloligand (termed Zn-HMTA), with free uncoordinated tertiary amine groups, has been synthesized via solution diffusion method for the first time. The crystal structure of 2D Zn-HMTA metalloligand was determined by the single crystal X-ray diffraction (SCXRD). The SCXRD and X-ray photoelectron spectroscopy (XPS) analyses have revealed that the 2D Zn-HMTA metalloligand is rich in- free tertiary amine groups, which are of strong coordination ability to transition metal ions (e.g. Ni2+, Co2+, Zn2+, Cu2+). As a result, a 2D bimetallic Co@Zn-HMTA MOFs was synthesized via coordination-assisted impregnation (CAI) strategy attributed to the unique feature of strong coordinated ability of free tertiary amine groups. Furthermore, a series of self-supported Co-ZnO-CN nanocatalysts were afforded upon the as-synthesized Co@Zn-HMTA MOFs served as a self-sacrificial template for pyrolysis at different temperatures. The optimized catalyst (termed as Co-ZnO@CN-CAI) demonstrated the excellent catalytic performance for hydrogenation-alkylation tandem reaction in comparison with the classic ZnO@CN composite (derived from Zn-HMTA MOFs) supported metallic Co catalyst (Co-ZnO@CN-IWI) prepared by incipient wetness impregnation method. Moreover, the kinetic study was also performed to confirm that the alkylation is the rate-determining step in the hydrogenation-alkylation tandem reaction. The origin of enhanced catalytic performance of Co-ZnO@CN-CAI and the role of Co@Zn-HMTA MOFs precursor have been explored by way of various characterizations, e.g. HADDF-STEM-EDS, SEM-EDS, 13C MAS NMR, XRD, Raman and XPS, etc. It is anticipated that the prepared low-cost and easily prepared 2D Zn-HMTA metalloligand will become a general template for synthesis of highly self-supported catalysts with coordination-assisted impregnation strategy (CAI) for various catalytic reactions.
A strategy of two-step tandem catalysis towards direct N-alkylation of nitroarenes with ethanol via facile fabricated novel Co-based catalysts derived from coordination polymers
Wang, Jing,Qi, Tianqinji,Li, Zhibin,She, Wei,Li, Xuewei,Li, Jingfang,Yan, Pengfei,Li, Weizuo,Li, Guangming
, p. 106 - 118 (2019/07/19)
Three novel N-doped carbon supported Co/Co3O4 catalysts, namely, Co@CN-hmta, Co@CN-larg and Co-Co3O4@CN-bipy, with sheet-, worm-, honeycomb-like morphologies respectively, have been fabricated by the pyrolysis of well-defined coordination polymers (CPs). Upon the as-prepared catalysts were applied for the reaction of N-alkylation of nitroarenes with ethanol, a direct two-step tandem reaction is realized, in which the Co@CN-hmta delivers 100% conversion/selectivity of N-ethylaniline/N,N-diethylaniline from the direct N-alkylation of nitroarenes with ethanol. The kinetic studies were conducted to confirm that the N-alkylation of aniline with ethanol is the rate-determining step in the two-step tandem reaction. The SEM/EDX, XRD, Raman, TEM, XPS, and CO2-TPD characterization results have revealed that sizes and dispersion of metallic Co, amount of structural defects and surface Lewis basicity towards three catalysts can be tuned by changing the structures of Co-based CPs designed by different organic linkers, which may also help to understand the preparation of industrial catalysts on a molecular level. The optimized Co@CN-hmta catalyst is easily recycled by using the external magnet for successive reuses without any loss in both activity and selectivity. To the best of our knowledge, this is the first carbon-nitrogen species supported Co/Co3O4 catalysts derived from the CPs, which could effectively catalyzed the N-alkylation of nitroarenes with ethanol to produce the secondary amines and/or tertiary amines. This low-cost, recyclable and easy scale-up N-doped carbon supported catalyst may be of potential application in various heterogeneous catalytic reactions.
The Role of N-Substituents in Radiationless Deactivation of Aminated Derivatives of a Locked GFP Chromophore
Baleeva, Nadezhda S.,Zaitseva, Snezhana O.,Gorbachev, Dmitriy A.,Smirnov, Alexander Yu.,Zagudaylova, Marina B.,Baranov, Mikhail S.
supporting information, p. 5219 - 5224 (2017/09/29)
We report the creation of a novel group of the ABDI-BF2 fluorescent dyes based on the conformationally locked GFP chromophore. We studied the intramolecular mechanism of radiationless deactivation of the ABDI-BF2 fluorophore by introducing the various substituents at the nitrogen atom. The results of this study and our previous work allowed us to claim that in case of ABDI-BF2 this deactivation is determined by the formation of the nonfluorescent internal charge transfer exited state with a planar quinoidal structure. The electronic effects have a greater impact on the radiationless deactivation than the conformation. Thus, the introduction of an electron-donating group is more effective than the creation of rigid derivatives. The presented dyes are characterized by high fluorescence quantum yields and pH-independence in the physiological pH range, making them promising candidates for a wide spectrum of fluorescence labeling applications.
A BODIPY fluorescence probe modulated by selenoxide spirocyclization reaction for peroxynitrite detection and imaging in living cells
Wang, Bingshuai,Yu, Fabiao,Li, Peng,Sun, Xiaofei,Han, Keli
, p. 383 - 390 (2013/02/22)
We present the synthesis, spectroscopic properties, and live-cell application of a new BODIPY (boron dipyrromethene) fluorescence probe BOD-Se based on selenoxide spirocyclization reaction for peroxynitrite detection. The probe employs BODIPY dye as fluorophore, and is integrated with a chemical peroxynitrite responsive organoselenium functional group. By using reactive diaryl selenide and modulating by intramolecular charge-transfer (ICT) process, the probe is employed for evaluating intracellular peroxynitrite level changes. Different intracellular peroxynitrite levels can be detected with BOD-Se by confocal microscopy experiments using mouse macrophage cell line RAW264.7.
Design, synthesis, and evaluation of resveratrol derivatives as Ass1-42 aggregation inhibitors, antioxidants, and neuroprotective agents
Lu, Chuanjun,Guo, Yueyan,Li, Jianheng,Yao, Meicun,Liao, Qiongfeng,Xie, Zhiyong,Li, Xingshu
supporting information, p. 7683 - 7687 (2013/02/21)
A series of novel resveratrol derivatives were designed, synthesised and evaluated as potential therapeutic agents for the treatment of Alzheimer's disease. Among these compounds, compound 7l, (E)-5-(4-(isopropylamino)styryl) benzene-1,3-diol, exhibited potent ss-amyloid aggregation inhibition activity, which was confirmed by a ThT fluorescence assay (71.65% at 20 μM) and transmission electron microscopy (TEM). Compound 7l also exhibited good antioxidant activity (4.12 Trolox equivalents in an oxygen radical absorbance capacity assay and a 37% reduction in reactive oxygen species in cells at 10 μM). The cytotoxicity analysis of compounds 7f, 7i, 7j and 7l indicated that these compounds have lower toxicities than resveratrol at 60 μM.
Multitarget-directed benzylideneindanone derivatives: Anti-β-amyloid (Aβ) aggregation, antioxidant, metal chelation, and monoamine oxidase B (MAO-B) inhibition properties against Alzheimer's disease
Huang, Ling,Lu, Chuanjun,Sun, Yang,Mao, Fei,Luo, Zonghua,Su, Tao,Jiang, Huailei,Shan, Wenjun,Li, Xingshu
, p. 8483 - 8492,10 (2020/09/15)
A novel series of benzylideneindanone derivatives were designed, synthesized, and evaluated as multitarget-directed ligands against Alzheimer's disease. The in vitro studies showed that most of the molecules exhibited a significant ability to inhibit self-induced β-amyloid (Aβ 1-42) aggregation (10.5-80.1%, 20 μM) and MAO-B activity (IC 50 of 7.5-40.5 μM), to act as potential antioxidants (ORAC-FL value of 2.75-9.37), and to function as metal chelators. In particular, compound 41 had the greatest ability to inhibit Aβ1-42 aggregation (80.1%), and MAO-B (IC50 = 7.5 μM) was also an excellent antioxidant and metal chelator. Moreover, it is capable of inhibiting Cu(II)-induced Aβ1-42 aggregation and disassembling the well-structured Aβ fibrils. These results indicated that compound 41 is an excellent multifunctional agent for the treatment of AD.
A Convenient Synthesis of Amines from Phenols
Goswami,Goswami,Borthakur,Rastogi
, p. 424 - 425 (2007/10/03)
A simple and convenient method for the conversion of substituted phenols into alkylated amines is described; the reaction proceeds via amide formation and subsequent rearrangement of the amide in the presence of alkali.
ACTIVATING EFFECT OF THE IMINIUM GROUP IN AROMATIC NUCLEOPHILIC SUBSTITUTION OF AN ALKOXY GROUP AND HALOGEN ATOMS BY THE ACTION OF NITROGEN BASES
Blokhin, A.V.,Bundel, Yu. G.,Terenin, V.I.,Kurtz, A.L.
, p. 2116 - 2123 (2007/10/02)
The characteristics of aromatic nucleophilic substitution with activation by the iminium group in the iminium derivatives of p-alkoxy- and p-halogenobenzaldehydes were investigated.They are determined by the concurrent addition of the nucleophilic agents at the C=N multiple bond.The activating effect of the iminium group depends on the nature of the leaving group, the solvent, the substituent in the benzene ring, and the nature and concentration of the protonating agent.The action of heat on p-methoxybenzylidenemethylamine with a tenfold excess of methylamine hydrochloride in a 30percent alcohol solution of methylamine at 150 deg C for 40 h leads to substitutioon of the methoxymethylamino group with a yield of 90percent.
ACTIVATING ACTION OF THE IMMONIUM GROUP IN THE SUBSTITUTION OF ALKOXYL AND HALOGEN ATOMS BY THE ALKYLAMINO GROUP IN THE BENZENE RING
Yudin, L. G.,Blokhin, A. V.,Bundel', Yu. G.,Simkin, B. Ya.,Terenin, V. I.
, p. 2064 - 2068 (2007/10/02)
The substitution of the alkoxy group in o-, p-, and m-alkoxybenzylidenedimethylimmonium iodides by the action of aliphatic amines was investigated.Only p-alkoxy derivatives enter into the reaction forming, after hydrolysis, p-alkyl- and p-dialkylaminobenzaldehydes.Substitution can also be realized in p-alkoxybenzaldehydes and Schiff bases in the presence of the amine hydrochloride.Similarly, the halogen atom in p-halogenobenzaldehydes is substituted by the aliphatic amine residue.Quantum-mechanical calculations of the energy of anionic localization and charge at the attacked carbon atom o f the benzene ring are consistent with the experimantal data.
