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71.
Rana Chatterjee Satyajit Samanta Anindita Mukherjee Sougata Santra Grigory V. Zyryanov Adinath Majee 《Tetrahedron letters》2019,60(3):276-283
We have observed that the allylic zinc halide under identical reaction conditions acts in different modes for different electrophiles. For Ts-aziridines the halide part of the allylic halide has been introduced as a nucleophile and for the carbonyl compounds the simple allylation reaction occurs. To the best of our knowledge this is the first report where the allylic zinc halide is the source of halide acting as nucleophile. The main advantages of the present procedure are easy to handle, no need of inert atmosphere, mild reaction conditions, and applicability to a wide variety of substrates for aziridines and carbonyl compounds. 相似文献
72.
73.
G-quadruplexes (G4) are the most actively studied non-canonical secondary structures formed by contiguous repeats of guanines in DNA or RNA strands. Small molecule mediated targeting of G-quadruplexes has emerged as an attractive tool for visualization and stabilization of these structures inside the cell. Limited number of DNA and RNA G4-selective assays have been reported for primary ligand screening. A combination of fluorescence spectroscopy, AFM, CD, PAGE, and confocal microscopy have been used to assess a dimeric carbocyanine dye B6,5 for screening G4-binding ligands in vitro and in cellulo. The dye B6,5 interacts with physiologically relevant DNA and RNA G4 structures, resulting in fluorescence enhancement of the molecule as an in vitro readout for G4 selectivity. Interaction of the dye with G4 is accompanied by quadruplex stabilization that extends its use in primary screening of G4 specific ligands. The molecule is cell permeable and enables visualization of quadruplex dominated cellular regions of nucleoli using confocal microscopy. The dye is displaced by quarfloxin in live cells. The dye B6,5 shows remarkable duplex to quadruplex selectivity in vitro along with ligand-like stabilization of DNA G4 structures. Cell permeability and response to RNA G4 structures project the dye with interesting theranostic potential. Our results validate that B6,5 can serve the dual purpose of visualization of DNA and RNA G4 structures and screening of G4 specific ligands, and adds to the limited number of probes with such potential. 相似文献
74.
Two silylene‐spaced ((E)‐vinylsilyl)anthracene‐dipyrromethane dyads have been designed and synthesized by RhCl(PPh3)3‐catalyzed hydrosilylation reactions of 5‐methyl‐5′‐(ethynylaryl)dipyrromethanes with (9‐Anthryl)‐dimethylsilane. The complexation studies of dyads toward different anions have also been performed, which reveal that dyads exhibit a highly selective response towards fluoride anion attributable to both hydrogen‐bonding and pentacoordination phenomena. This dual‐mode fluoride recognition event is unprecedented and may pave the way for future developments in the areas of porphyrinoids, organosilicon, polymer, and supramolecular chemistry. 相似文献
75.
76.
D. Bhaskar Reddy P. V. Ramana Reddy M. Muralidhar Reddy M. V. Ramana Reddy S. Vijayalakshmi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):325-329
Abstract Some new 1,1,2-trisubstituted ethylenic sulfones have been prepared by the condensation of aryl- and benzylsulfonylmethylsulfonylacetic acid esters with araldehydes. 相似文献
77.
A Facile and Convenient Method for the Synthesis of 8-Methoxy 10,11-Dihydronaphtho [1,2-b]Quinolines
Dihydronaphthoquinolines are relatively rare polycyclic heterocyclic compounds. We wish to report a simple and convenient preparative method for hitherto unknown compounds with these new structural features. 6-methoxy tetralone1 (I) 3.5g (.02 mole) in 3 ml DMF was added slowly to 4.6g (.02 mole) of POCl3 in 3ml DMF at 0°C. The mixture was stirred for 5 hrs. and the temp. was then gradually raised from 0° to 60–65°C. The resultant complex was treated with aq. sodium acetate solution till pH5–6 was reached. The extract on usual purification, furnished 3.2g (80°%.) of 1-chloro, 6-methoxy, 1,2,3,4 tetrahydro naphthalene-2-aldehyde(II)+2 相似文献
78.
Dipak Ghosh Madhumita Lahiri Argha Deb Susobhan Das Krishnadas Purkait Biswanath Biswas Jayanta Roy Choudhury Rini Chatterjee Abdul Kayum Jafry 《The European Physical Journal C - Particles and Fields》2011,71(1):243-249
The scaled factorial moments and the multifractal moments have been investigated in different??-intervals to study the dynamical fluctuation of pions produced in 200 AGeV32S-Ag/Br interaction. In order to investigate the detail characteristics of intermittency behaviour, theF-moments are extracted up to the eighth order of moments in differentM-intervals. The analysis indicates a non-thermal phase transition and different regime of particle production during the hadronisation process. 相似文献
79.
D. Bhaskar Reddy N. Chandrasekhar Babu V. Padmavathi A. Padmaja 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):237-242
Abstract Different heteroatoms viz., N, S & Se have been incorporated into 2-arylethenyl-2′-arylethynyl sulfones by nucleophilic reaction with benzylmine, hydrogen sulfide and sodium hydrogen selenide. 相似文献
80.
Abstract Selective interpolymer complexation has been studied between methacrylic acid-methacrylamide copolymer and some complementary polymers such as poly(methacrylamide), poly(vinyl pyrrolidone), and poly(ethylene oxide). The relative order of complexation ability of the various nonionic polymers has been interpreted on the basis of the nature of interactions between different units of polymers. Configurational environment and neighboring group influences seem to affect interpolymer complex formation. 相似文献