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Dr. Longyang Dian Dr. Daniel S. Müller Prof. Dr. Ilan Marek 《Angewandte Chemie (International ed. in English)》2017,56(24):6783-6787
The highly diastereo- and enantioselective formation of polysubstituted cyclopropanes was easily achieved through the asymmetric copper-catalyzed carbomagnesiation reaction of nonfunctionalized cyclopropene derivatives. The carbometalated species generated in situ readily undergo C−C and C−X bond-forming reactions with various electrophiles with complete retention of configuration. 相似文献
916.
Zbigniew Grobelny Marek Matlengiewicz Kinga Skrzeczyna Sylwia Golba Justyna Jurek-Suliga 《International Journal of Polymer Analysis and Characterization》2015,20(5):457-468
Anhydrous alkali metal hydroxide (KOH, NaOH, and LiOH)-activated macrocyclic ligand complexing metal cations, i.e., coronands 12C4, 15C5, 18C6, DCH24C8, and cryptand C222, were selected for initiation of β-butyrolactone (β-BL) and ε-caprolactone (ε-CL) polymerization. It was found that β-BL polymerizes in the presence of KOH/18C6, KOH/C222, and NaOH/C222 systems. The real initiators in this case are two salts, potassium 3-hydroxybutyrate and potassium trans-crotonate, which are responsible for the formation of two fractions of the obtained polymer. ε-CL underwent polymerization with KOH or NaOH activated by all ligands used or without the ligand but with LiOH/12C4. Using KOH-activated strong ligands, i.e., 15C5, 18C6, or C222, two polymer fractions were generated containing linear and, unexpectedly, also cyclic macromolecules. The mechanism of the studied processes is discussed. 相似文献
917.
SnS and SnS2 thin films deposited using a spin‐coating technique from intramolecularly coordinated organotin sulfides
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Tomáš Řičica Lukáš Střižík Libor Dostál Marek Bouška Milan Vlček Ludvík Beneš Tomáš Wágner Roman Jambor 《应用有机金属化学》2015,29(3):176-180
Synthesis and applications of organotin(II) sulfide ({2,6‐(Me2NCH2)2C6H3}Sn)2(μ‐S) ( 1 ), organotin(II) thiophenolate {2,6‐(Me2NCH2)2C6H3}Sn(SPh) ( 2 ) and organotin(IV) heptasulfide {2,6‐(Me2NCH2)2C6H3}2Sn2S7 ( 3 ) as potential single‐source precursors (SSPs) for the deposition of SnS or SnS2 thin films using a spin‐coating method are reported. Compounds 1 , 2 and 3 differ either by tin oxidation state or by Sn:S ratio (Sn:S = 2:1 in 1 , 1:1 in 2 and 2:7 in 3 ). It is shown that compound 1 is not a suitable SSP for thin‐film fabrication using the spin‐coating process because of its incomplete decomposition at annealing temperature. However, compounds 2 and 3 seem to be promising SSPs for spin‐coating of amorphous semiconducting thin films of SnS and SnS2, respectively. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
918.
Hruška Branislav Dagupati Rajesh Chromčíková Mária Nowicka Aleksandra Macháček Jan Liška Marek Munoz Francisco 《Journal of Thermal Analysis and Calorimetry》2020,140(5):2033-2054
Journal of Thermal Analysis and Calorimetry - Convection heat transfer in cavities has attracted much attention from researchers. Many kinds of nanofluids have exhibited non-Newtonian behavior and... 相似文献
919.
Dr. Krzysztof Durka Paulina H. Marek-Urban Krzysztof Nowicki Jakub Drapała Dr. hab. Katarzyna N. Jarzembska Piotr Łaski Aleksandra Grzelak Dr. Marek Dąbrowski Prof. Krzysztof Woźniak Prof. Sergiusz Luliński 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(14):e202104492
The approach to a series of six- and seven-membered oxaboraheterocycles based on naphthalene or biphenyl backbones was developed. The key synthetic step involved Br/Li exchange in respective potassium (bromoaryl)trifluoroborates followed by quenching with selected electrophiles (CO2, DMF, Me2Si(H)Cl) and hydrolytic workup. Two ring-expanded benzoxaborole congeners were obtained by an additional reduction step with LiAlH4 or NaBH4. The obtained boracyclic compounds were characterized in detail by NMR spectroscopy and single-crystal X-ray diffraction. Specifically, biphenyl-based systems show dynamic behaviour interpreted in terms of inversion of non-planar seven-membered boraheterocycles. The acidity of the obtained compounds varies very strongly (pKa ranges from 3.1–9.6) depending on their structure. Due to the enhanced boron Lewis acidity, selected compounds were used as a basis for luminescent complexes with 8-hydroxyquinoline. A strong phase-dependent variation of emission-band maximum (480–527 nm) and photoluminescence quantum yield (10–95 %) was observed, which was rationalized in terms of specific aggregation effects. 相似文献
920.
Molecular architecture of novel potentially bioactive (co)oligoesters containing pesticide moieties established by electrospray ionization multistage mass spectrometry
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