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61.
Mohammad Shahidul Islam M. Ali Abdullah Mohammed Al-Majid Abdullah Saleh Alamary Saeed Alshahrani Sammer Yousuf Muhammad Iqbal Choudhary Assem Barakat 《Molecules (Basel, Switzerland)》2021,26(8)
The Friedel–Crafts reaction between substituted indoles as nucleophiles with chalcones-based benzofuran and benzothiophene scaffolds was carried out by employing a highly efficient bimetallic iron–palladium catalyst system. This catalytic approach produced the desired bis-heteroaryl products with low catalyst loading, a simple procedure, and with acceptable yield. All synthesized indole scaffolds 3a–3s were initially evaluated for their cytotoxic effect against human fibroblast BJ cell lines and appeared to be non-cytotoxic. All non-cytotoxic compounds 3a–3s were then evaluated for their anticancer activities against cervical cancer HeLa, prostate cancer PC3, and breast cancer MCF-7 cell lines, in comparison to standard drug doxorubicin, with IC50 values 1.9 ± 0.4 µM, 0.9 ± 0.14 µM and 0.79 ± 0.05 µM, respectively, and appeared to be moderate to weak anticancer agents. Fluoro-substituted chalcone moiety-containing compounds, 3b appeared to be the most active member of the series against cervical HeLa (IC50 = 8.2 ± 0.2 µM) and breast MCF-7 cancer cell line (IC50 = 12.3 ± 0.04 µM), whereas 6-fluroindol-4-bromophenyl chalcone-containing compound 3e (IC50 = 7.8 ± 0.4 µM) appeared to be more active against PC3 prostate cancer cell line. 相似文献
62.
63.
Cover Picture: Double CaromH Activation Associated with Etheral Oxygen Insertion to Phenazine Architecture in Oxidisable Ruthenium(III) Complexes: A Mechanistic Insight (Chem. Eur. J. 10/2014)
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64.
N‐Heterocyclic Carbene,High Oxidation State Molybdenum Alkylidene Complexes: Functional‐Group‐Tolerant Cationic Metathesis Catalysts
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Prof. Michael R. Buchmeiser M. Sc. Suman Sen Dr. Jörg Unold Dr. Wolfgang Frey 《Angewandte Chemie (International ed. in English)》2014,53(35):9384-9388
We synthesized the first N‐heterocyclic carbene (NHC) complexes of Schrock’s molybdenum imido alkylidene bis(triflate) complexes. Unlike existing bis(triflate) complexes, the novel 16‐electron complexes represent metathesis active, functional‐group‐tolerant catalysts. Single‐crystal X‐ray structures of two representatives of this novel class of Schrock catalysts are presented and reactivity is discussed in view of their structural peculiarities. In the presence of monomer (substrate), these catalysts form cationic species and can be employed in ring‐closing metathesis (RCM), ring‐opening metathesis polymerization (ROMP), as well as in the cyclopolymerization of α,ω‐diynes. Monomers containing functional groups, which are not tolerated by the existing variations of Schrock’s catalyst, e.g., sec‐amine, hydroxy, and carboxylic acid moieties, can be used. These catalysts therefore hold great promise in both organic and polymer chemistry, where they allow for the use of protic monomers. 相似文献
65.
Sharma Deepika Radha Anu Kumar Pretam Kumar Sandeep Jassal Amanpreet K. Lata Suman Vikas Pandey Sushil K. 《Transition Metal Chemistry》2020,45(8):531-544
Transition Metal Chemistry - Nickel(II) complexes with octahedral coordination stabilized by N-donor ligands corresponds to [{(ArO)2PS2}2Ni·L2] [Ar = 4-(C2H5)C6H4 (3), and... 相似文献
66.
Ranjit Bag Sourav Kar Suvam Saha Suman Gomosta Beesam Raghavendra Thierry Roisnel Sundargopal Ghosh 《化学:亚洲杂志》2020,15(6):780-786
Triply‐bridging bis‐{hydrido(borylene)} and bis‐borylene species of groups 6, 8 and 9 transition metals are reported. Mild thermolysis of [Fe2(CO)9] with an in situ produced intermediate, generated from the low‐temperature reaction of [Cp*WCl4] (Cp*=η5‐C5Me5) and [LiBH4?THF] afforded triply‐bridging bis‐{hydrido(borylene)}, [(μ3‐BH)2H2{Cp*W(CO)2}2{Fe(CO)2}] ( 1 ) and bis‐borylene, [(μ3‐BH)2{Cp*W(CO)2}2{Fe(CO)3}] ( 2 ). The chemical bonding analyses of 1 show that the B?H interactions in bis‐{hydrido (borylene)} species is stronger as compared to the M?H ones. Frontier molecular orbital analysis shows a significantly larger energy gap between the HOMO‐LUMO for 2 as compared to 1 . In an attempt to synthesize the ruthenium analogue of 1 , a similar reaction has been performed with [Ru3(CO)12]. Although we failed to get the bis‐{hydrido(borylene)} species, the reaction afforded triply‐bridging bis‐borylene species [(μ3‐BH)2{WCp*(CO)2}2{Ru(CO)3}] ( 2′ ), an analogue of 2 . In search for the isolation of bridging bis‐borylene species of Rh, we have treated [Co2(CO)8] with nido‐[(RhCp*)2(B3H7)], which afforded triply‐bridging bis‐borylene species [(μ3‐BH)2(RhCp*)2Co2(CO)4(μ‐CO)] ( 3 ). All the compounds have been characterized by means of single‐crystal X‐ray diffraction study; 1H, 11B, 13C NMR spectroscopy; IR spectroscopy and mass spectrometry. 相似文献
67.
Soujan Ghosh Swati Chowdhury Subrata Kundu Sudipta Sasmal Dimitrios Z. Politis Stelios M. Potirakis Masashi Hayakawa Suman Chakraborty Sandip K. Chakrabarti 《Entropy (Basel, Switzerland)》2022,24(1)
We focus on the possible thermal channel of the well-known Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) mechanism to identify the behavior of thermal anomalies during and prior to strong seismic events. For this, we investigate the variation of Surface Latent Heat Flux (SLHF) as resulting from satellite observables. We demonstrate a spatio-temporal variation in the SLHF before and after a set of strong seismic events occurred in Kathmandu, Nepal, and Kumamoto, Japan, having magnitudes of 7.8, 7.3, and 7.0, respectively. Before the studied earthquake cases, significant enhancements in the SLHF were identified near the epicenters. Additionally, in order to check whether critical dynamics, as the signature of a complex phenomenon such as earthquake preparation, are reflected in the SLHF data, we performed a criticality analysis using the natural time analysis method. The approach to criticality was detected within one week before each mainshock. 相似文献
68.
69.
G. Dixit J. P. Singh R. C. Srivastava H. M. Agrawal R. J. Choudhary A. Gupta 《Surface and interface analysis : SIA》2010,42(3):151-156
Nickel ferrite is a soft magnetic material with inverse spinel structure. Soft ferrite films are used in microwave devices, integrated planar circuits, etc., because of their high resistivity. In this work, thin films of nickel ferrite were deposited on Si (100) substrate by using pulsed laser deposition (PLD) technique. The thickness of the film was measured by surface profilometer and also by X‐ray reflectivity (XRR). The films were annealed at three different temperatures to observe the effect on the structural and magnetic properties of the film. The films were characterised by X‐ray diffraction (XRD), Raman spectroscopy and vibrating sample magnetometer (VSM) to study the structural and magnetic properties. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
70.
The curing behaviour of diglycidyl ether of bisphenol-A (DGEBA) was investigated by the dynamic differential scanning calorimetry
using varying molar ratios of aromatic imide-amines and 4,4′-diaminodiphenylsulfone (DDS). The imide-amines were prepared
by reacting 1 mole of naphthalene 1,4,5,8-tetracarboxylic dianhydride (N) and 4,4′-oxodiphthalic anhydride (O) with 2.5 moles
of 4,4′-diaminodiphenyl ether (E) or 4,4′-diaminodiphenyl methane (M) or 4,4′-diaminodiphenylsulfone (S) and designated as
NE/OE or NM/OM or NS/OS. The mixture of the imide-amines and DDS at ratio of 0:1, 0.25:0.75, 0.5:0.5, 0.75:0.25 and 1:0 were
used to investigate the curing behaviour of DGEBA.
A single exotherm was observed on curing with mixture of imide-amines and DDS. This clearly shows that the two amines act
as co-curing agents. Curing temperatures were higher with imide-amines having sulfone linkage irrespective of anhydride. Curing
of DGEBA with mixture of imide-amines and or DDS resulted in a decrease in characteristic curing temperatures. The thermal
stability of the isothermally cured resins was also evaluated using dynamic thermogravimetry in a nitrogen atmosphere. The
char yield was higher in case of resins cured imide-amines based on N and E. The activation energy of decomposition and integral
procedural decomposition temperature were also calculated from the TG data. 相似文献