Search results for "Bromide"
showing 10 items of 591 documents
ChemInform Abstract: Remarkable Effect of Lithium Bromide in the Enantioselective Protonation with α-Sulfinyl Alcohols.
2010
Abstract The favourable effect of lithium bromide enhancing the facial enantioselectivity in the protonation of methyl tetralone enolate with α-sulfinyl alcohols is described. Theoretical calculations allow to propose a model to explain the stereochemical course of the protonation reaction.
Remarkable effect of lithium bromide in the enantioselective protonation with α-sulfinyl alcohols
1998
Abstract The favourable effect of lithium bromide enhancing the facial enantioselectivity in the protonation of methyl tetralone enolate with α-sulfinyl alcohols is described. Theoretical calculations allow to propose a model to explain the stereochemical course of the protonation reaction.
ChemInform Abstract: Selective “One-Pot” Synthesis of Functionalized Cyclopentenones.
2012
Reaction of squaric acid derivatives with vinyl magnesium bromide followed by treatment with trifluoroethanol allows a new and stereoselective access to functionalized cyclopentenones of type (III)/ (V).
p-Di-(1-phenylvinyl)-Benzol und seine reaktion mit elektronenüberträgern
1972
p-Di-(1-phenylvinyl)-benzol (I) wurde, ausgehend von p-Diacetylbenzol und Phenylmagnesiumbromid, in hoher Reinheit und guter Ausbeute dargestellt und charakterisiert. I setzt sich spontan mit Elektronenubertragern (Natrium, Naphthalin-Natrium) unter Ausbildung einer tief violetten Farbung um. Es entstehen die Oligomeren bis zum Dekameren, wobei die geradzahligen Homologen in hoherer Konzentration vorliegen als die jeweils benachbarten ungeradzahligen. Die Ergebnisse werden diskutiert. p-Di-(1-phenylvinyl) benzene (I) was prepared from diacetyl benzene and phenyl magnesium bromide in high purity and with good yield. It was identified by IR, NMR, and elemental analysis. I reacts immediately w…
Alkylation of RNA by Vinyl Chloride and Vinyl Bromide Metabolites in Vivo: Effect on Protein Biosynthesis
1981
Alkylation of DNA is viewed as representing the initial critical step in carcinogenesis induced by chemical substances. Vinyl chloride and vinyl bromide, compounds with proven carcinogenic potency toward the liver, are biotransformed to reactive metabolites which covalently bind to DNA (see Bolt et al. 1980). Furthermore, extensive covalent binding of metabolites of both vinyl chloride (Laib and Bolt 1977, 1978) and vinyl bromide (Ottenwalder et al. 1979) occurs to RNA of liver when rats are exposed to both vinyl halides. Defined products of alkylation are 1,N6-ethenoadenosine (Laib and Bolt 1777; Ottenwalder et al. 1979) and 3,N4-ethenocytidine (Laib and Bolt 1978; Ottenwalder et al. 1979)…
Metabolic Activation and Pharmacokinetics in Hazard Assessment of Halogenated Ethylenes
1981
Halogenated ethylenes play an important role in occupational and environmental medicine. Several attempts at toxicological evaluation of such compounds have been recently published (Maltoni 1977; Lee et al. 1978; Gehring et al. 1979; Kappus and Ottenwalder 1980; Henschler et al. 1980; Bolt 1980). The principal question is that of possible carcinogenicity. It is now clear that vinyl chloride (Maltoni 1977) and vinyl bromide (Bolt et al. 1979) are carcinogenic; some data also argue in favor of carcinogenicity of vinylidene chloride (Lee et al. 1978). Trichloroethylene (Henschler et al. 1980) and perchloroethylene (Bolt and Link 1980), according to present data, appear devoid of cancerogenic p…
A Versatile Palladium/Triphosphane System for Direct Arylation of Heteroarenes with Chloroarenes at Low Catalyst Loading
2010
International audience; Put a ring on it: The use of an air-stable, robust palladium/tridentate phosphane catalyst in direct C[BOND]H and C[BOND]Cl activation reactions is reported (see scheme; DMAc=N,N-dimethylacetamide, TBAB=tetra-n-butylammonium bromide). Electron-rich, electron-poor, and polysubstituted furans (X=O), thiophenes (X=S), pyrroles (X=NR5), and thiazoles were arylated with chloroarenes in the presence of the catalyst.
Chiroptical Phenomena in Reverse Micelles: The Case of (1R,2S)- Dodecyl (2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium Bromide (DMEB)
2014
(1R,2S)-Dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) aggregates dispersed in carbon tetrachloride have been investigated by Fourier transform infrared (FT-IR), vibrational circular dichroism (VCD) and 1H nuclear magnetic resonance (NMR) spectroscopy at various surfactant concentration and water-to-surfactant molar ratio. Experimental data indicate that, even at the lowest investigated concentration and in absence of added water, DMEBmolecules associate in supramolecular assemblies. At higherDMEBconcentration the aggregates can confine watermolecules,making it plausible to think thatDMEB form reverse micelles and that watermolecules are quite uniformly distributed…
Crystal structure of 3-mesityl-1-[(pyridin-2-yl)methyl]-3,4,5,6-tetrahydropyrimidin-1-ium bromide monohydrate
2015
In the title hydrated salt, C19H24N3+·Br−·H2O, the values of the N—C bond lengths within the tetrahydropyrimidinium ring indicate delocalization of the N=C double bond. In the cation, the dihedral angle formed by the pyridine and benzene rings is 14.97 (12)°. In the crystal, ions and water molecules are linked by O—H...Br, O—H...N, C—H...Br and C—H...O hydrogen bonds into chains running parallel to thebaxis.
Crystal structure and Hirshfeld surface analysis of a pyridiniminium bromide salt: 1-[2-(adamantan-1-yl)-2-oxoethyl]pyridin-4-iminium bromide
2018
The asymmetric unit of the title pyridiniminium halide salt comprise of one cation and one anion. In the crystal, molecules are linked by N—H⋯Br and C—H⋯O hydrogen bonds, C—H⋯π interactions, and π–π interactions into layers. The intermolecular interactions in the crystal structure are quantified by Hirshfeld surface analysis.