نتایج جستجو برای: halide substituents
تعداد نتایج: 13951 فیلتر نتایج به سال:
While H2O2 is a powerful oxidant, decomposing into environmentally benign H2O and O2, a catalyst is often required for reactions with H2O2 to proceed at synthetically useful rates. Organotellurium and organoselenium compounds catalyze the oxidation of halide salts to hypohalous acids using H2O2. When sequestered into xerogel monoliths, the xerogel-chalcogenide combinations have demonstrated inc...
The N-arylindole subunit is an important species in many biologically active and pharmaceutically important compounds, which display antiestrogen [1], analgesic [2], antiallergy [3], antimicrobial [4], and neuroleptic activity [5]. Although the traditional coppercatalyzed coupling of an aryl halide with a heteroatombased nucleophile, the Ullmann-type coupling reaction, has remained a standard m...
Lewis pair polymerization employing N-Heterocyclic olefins (NHOs) and simple metal halides as co-catalysts has emerged as a useful tool to polymerize diverse lactones. To elucidate some of the mechanistic aspects that remain unclear to date and to better understand the impact of the metal species, computational methods have been applied. Several key aspects have been considered: (1) the formati...
Silicon and germanium containing pyridine aldoxime, ketoxime and amidoxime O-ethers have been prepared using phase transfer catalytic systems oxime alkyl halide solid KOH 18-crown-6 benzene and oxime alkyl halide solid K(2)CO(3) or Cs(2)CO(3) 18-crown-6 toluene. Cytotoxic activity of silicon and germanium containing pyridine oxime O-ethers was tested in vitro on two monolayer tumor cell lines: ...
A few classes of ionic liquids were synthesized and investigated for their physical properties as a function of structural variation. Bis(oxalato)borate (BOB) and bis(trifluoromethylsulfonyl)imide (NTf2) ionic liquids (ILs) containing pyridinium, 4dimethylaminopyridinium (DMAP) and pyrrolidinium cations bearing alkyl, benzyl, hydroxyalkyl and alkoxy substituents, were prepared from the correspo...
The pyridine heterocycle continues to play a vital role in the development of human medicines. More than 100 currently marketed drugs contain this privileged unit, which remains highly sought after synthetically. We report an efficient means to access di- and trisubstituted pyridines in an efficient and highly controlled manner using transient 3,4-pyridyne intermediates. Previous efforts to emp...
By using DABCO·(SO(2))(2), DABSO, as a solid bench-stable SO(2)-equivalent, the palladium-catalysed aminosulfonylation of aryl-, alkenyl- and heteroaryl halides has been achieved. N,N-Dialkylhydrazines are employed as the N-nucleophiles and provide N-aminosulfonamides as the products in good to excellent yields. The reactions are operationally simple to perform, requiring only a slight excess o...
The reactions of group 13 metal trichlorides with aromatic azides were examined by CW EPR and pulsed ENDOR spectroscopies. Complex EPR spectra were obtained from reactions of aluminium, gallium and indium trichlorides with phenyl azides containing a variety of substituents. Analysis of the spectra showed that 4-methoxy-, 3-methoxy- and 2-methoxyphenyl azides all gave 'dimer' radical cations [Ar...
Isospecific polymerization of polar styrenes is a challenge polymer science. Particularly challenging are monomers bearing electron-withdrawing substituents or bulky substituents. Here, we report the coordination halide- and amino-functionalized including para-fluorostyrene (pFS), para-chlorostyrene (pClS), para-bromostyrene (pBrS), para-(N,N-diethylamino)styrene (DMAS) using 2,2′-sulfur-bridge...
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