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991.
The reactions of 2,4,6-trinitrotoluene with alkanethiols in the presence of K2CO3 (the molar ratio of the reactants is 1 : 1 : 1) in dipolar aprotic solvents result in selective replacement of the ortho-nitro group to form 2-alkylthio-4,6-dinitrotoluenes, which can be oxidized to the corresponding sulfoxides or sulfones. The second ortho-nitro group can be replaced under the action of one more equivalent of alkanethiol on sulfides as exemplified in PhCH2SH. 相似文献
992.
V. N. Britsun A. N. Esipenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2008,44(12):1429-1459
Data from the last six years on the heterocyclization of thioamides containing an active methylene group are analyzed and
classified.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1763–1800, November, 2008. 相似文献
994.
Fred U. Nnamdi Dr. Colin Diner Prof. Pier Alexandre Champagne Prof. Michael G. Organ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(11):3855-3860
Two similar tridentate directing groups derived from glycine and 8-aminoquinoline were shown to enable the palladium-catalyzed anti-Markovnikov hydrofunctionalization of 4-pentenylamine with drastically different efficiencies. A computational investigation into the origin of the reactivity difference between these isomeric, carbonyl-transposed auxiliaries suggests that protonation state, thus charge of the substrate-metal complex prior to nucleopalladation is key. These investigations have culminated in a directing group design that can undergo Pd-catalyzed hydrofunctionalization under relatively mild conditions, as low as room temperature. 相似文献
995.
In this paper, we introduce the concept of topological hypergroups as a generalization of topological groups. A topological hypergroup is a nonempty set endowed with two structures, that of a topological space and that of a hypergroup. Let (H, ○) be a hypergroup and (H, τ) be a topological space such that the mappings (x, y) → x ○ y and (x, y) → x/y from H × H to 𝒫*(H) are continuous. The main tool to obtain basic properties of hypergroups is the fundamental relation β*. So, by considering the quotient topology induced by the fundamental relation on a hypergroup (H, ○) we show that if every open subset of H is a complete part, then the fundamental group of H is a topological group. It is important to mention that in this paper the topological hypergroups are different from topological hypergroups which was initiated by Dunkl and Jewett. 相似文献
996.
SnO2 rods have been synthesized by using tin (II) chain‐like complexes as precursors in which oxalate and ethylene glycol act as co‐ligands. On the basis of experimental analysis, a reasonable formation mechanism of rods is discussed, which is further supported by Fourier transform infrared spectroscopy (FT‐IR). These results show that the synergistic effect of oxalate group and ethylene glycol plays an important role in the formation of long SnO2 rods. 相似文献
997.
998.
Rajoshree Bandyopadhyay 《Journal of organometallic chemistry》2010,695(7):1012-10984
The treatment of tin(II) trifluoromethanesulfonate with three differently-sized crown ethers [12]crown-4, [15]crown-5 and [18]crown-6 results in the formation of tin complexes that exhibit dramatically different structural features. The compounds are investigated using experimental techniques and density functional theory calculations. 相似文献
999.
1000.
Michio Umino 《The Journal of mathematical sociology》2013,37(4):237-246
This paper examines Dawes (1975) model on commons dilemma (CD) situation and proposes an alternative model which formulates CD. Firstly, it makes clear that Dawes model does not have the characteristics of CD. Secondly, it specifies “resource unit condition” which models of commons dilemma must satisfy. Thirdly, it presents CD model, which is obtained by setting the condition in Dawes model. And lastly, it examines some nature of the proposed model and find that in CD situation, fine is distributed proportionally to each player's property. 相似文献