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101.
102.
Marcin Śnieżek Sebastian Stecko Irma Panfil Bartłomiej Furman Zofia Urbańczyk-Lipkowska Marek Chmielewski 《Tetrahedron: Asymmetry》2013,24(2-3):89-103
The stereoselectivity of 1,3-dipolar cycloaddition reactions of C-phenyl open-chain nitrones and α,β-unsaturated γ- and δ-lactones was investigated under thermal and catalytic conditions. It was found that under thermal conditions, the endo approach of the reactants was preferred leading to the thermodynamic product. In the presence of Sc(OTf)3 the exo adduct was obtained in high yield and selectivity. The energies of the cycloaddition reactions were investigated by means of molecular orbital calculations at the B3LYP/6-31+G(d,p) and MP3/6-31+G(d,p) theory level. Different reaction channels and reactant approaches, fitting the individual regio- and stereochemical preferences, are discussed. The computational results were compared with the corresponding experimental data and found to be in good agreement. 相似文献
103.
Jaworski Jan S. Bankiewicz Barbara Krygowski T. Marek Palusiak Marcin Stasyuk Olga A. Szatylowicz Halina 《Structural chemistry》2016,27(4):1279-1289
Structural Chemistry - Intermolecular interactions between molecules of protic solvents (water, methanol, formic acid, formamide, methylamine and ammonia) and monatomic ions (Li+, Na+, K+,... 相似文献
104.
A convenient preparation of alkyl nitriles from alkyl halides is described. Acetone cyanohydrin is employed as the source of cyanide ion. 相似文献
105.
Triphenylamine derivatized phenylacetylene macrocycle with large two-photon absorption cross-section
Zhen Fang Marek SamocRichard D. Webster Anna SamocYee-Hing Lai 《Tetrahedron letters》2012,53(36):4885-4888
A phenylacetylene macrocycle (PAM) derivative containing triphenylamine as the framework was synthesized in one-step Sonogashira coupling. The photophysical and electrochemical properties were investigated in details. This hexamer shows significant enhancement in two-photon absorption cross-section relative to reported PAM derivatives. 相似文献
106.
A new class of stereoregular vinylene‐arylene copolymers with double‐decker silsesquioxane in the main chain 下载免费PDF全文
Michał Dutkiewicz Monika Ludwiczak Bogdan Marciniec Marek Nowicki 《Journal of polymer science. Part A, Polymer chemistry》2016,54(8):1044-1055
A synthesis of a new macromolecular class of vinylene‐arylene copolymers with double‐decker silsesquioxane in the main chain is presented. Two transition‐metal‐catalyzed processes, which is silylative‐coupling copolycondensation (SCC) and ADMET copolymerization of divinyl‐substituted double‐decker silsesquioxanes (DDSQ‐2SiVi) with selected diolefins, are reported to be highly efficient tools for the formation of stereoregular copolymers containing DDSQ‐silylene‐vinylene‐arylene units. The copolymeric products are studied in terms of their structural, thermal, and mechanical properties. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1044–1055 相似文献
107.
108.
Robert Łysek Ewa Woźny Marek Chmielewski 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):327-340
Chiral formates derived from propane-1,2-diol, 1,2- O -isopropylidene- f - D -xylo- and f - D -gluco-furanoses were subjected to treatment with cyclopentadienyl [tris(trimethylsilylmethyl)] titanium (IV). A mixture of the corresponding ( E )- and ( Z )- g -silylvinyl ethers were obtained with predominance of the former. It was found that in contrast to ( Z )-vinyl ethers, which give g -lactams with chlorosulfonyl isocyanate, the ( E )-vinyl ethers gave unstable cycloadducts which undergo rapid elimination reaction leading to ( E )- f , g -unsaturated amides. 相似文献
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110.
Przemysław Rybiński Grażyna Janowska Małgorzata Jóźwiak Marek Jóźwiak 《Journal of Thermal Analysis and Calorimetry》2013,113(1):43-52
The article presents the effect of attapulgite (ATT) and its synergic action with carbon or silica on the thermal properties and flammability of cross-linked styrene–butadiene rubber. It has been shown that ATT is active filler improving the thermal and mechanical properties of composites containing this aluminosilicate. The decreased flammability of vulcanizates containing ATT compared to that of unfilled vulcanizates results from good insulating properties of the ATT used. The considerable reduction in the flammability of composites containing ATT and carbon nanofiber or silica is connected, first of all, with the formation of a homogeneous boundary layer. 相似文献