The Experts below are selected from a list of 2337 Experts worldwide ranked by ideXlab platform
Henri Doucet - One of the best experts on this subject based on the ideXlab platform.
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Palladium-catalysed direct heteroarylation of Bromobenzenes bearing SO2R substituents at C2 or C4
RSC Advances, 2015Co-Authors: Charles Beromeo Bheeter, Rongwei Jin, Jitendra K. Bera, Henri DoucetAbstract:Palladium-catalysed direct arylation of 4- or 2-Bromobenzenesulfonic acid derivatives in the presence of a variety of heteroaromatics was found to proceed using 0.1-0.5 mol% palladium acetate as the catalyst. However, both the nature and position of the SO2R substituent on such Bromobenzenes has an influence on the reaction rates and yields. The presence of SO2Et or SO2NEt2 at the C2 or C4 position of Bromobenzene is tolerated. Good results were also obtained from Bromobenzene substituted at C4 by SO2NHPh or SO2OPh. On the other hand, the reactions of Bromobenzenes bearing either SO2N(Me)CH2Ph or SO2OAr at C2 led in some cases to intramolecular reactions instead of the desired intermolecular couplings. Some reactions were performed in cyclopentyl methyl ether, which can be considered as a green solvent.
Robert P Hanzlik - One of the best experts on this subject based on the ideXlab platform.
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a proteomic analysis of Bromobenzene reactive metabolite targets in rat liver cytosol in vivo
Chemical Research in Toxicology, 2007Co-Authors: Yakov M Koen, Natalia V Gogichaeva, Michail A Alterman, Robert P HanzlikAbstract:Metabolic activation and protein covalent binding are early and apparently obligatory events in the cytotoxicity of many simple organic chemicals including drugs and natural products. Although much has been learned about the chemistry of reactive metabolite formation and reactivity toward protein nucleophiles, progress in identifying specific protein targets for reactive metabolites of various protoxins has been much slower. We previously reported nine microsomal and three cytosolic proteins as targets for reactive metabolites of Bromobenzene in rat liver. These results, and contemporary work by others, indicate that protein covalent binding is not totally random in cells. Moreover, as protein targets for other protoxins were identified, little commonality of target proteins became apparent. In the present work, we used two-dimensional gel electrophoresis to separate liver cytosolic proteins from rats treated with 14C-Bromobenzene; 110 of the 836 observed spots contained measurable radioactivity that vari...
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identification of three protein targets for reactive metabolites of Bromobenzene in rat liver cytosol
Chemical Research in Toxicology, 2000Co-Authors: Yakov M Koen, Todd D Williams, Robert P HanzlikAbstract:The hepatotoxicity of Bromobenzene and many other simple organic chemicals is believed to be associated with covalent binding of chemically reactive metabolites to cellular proteins. Recently, a rat liver microsomal esterase was shown to be targeted by Bromobenzene metabolites formed in vitro [Rombach, E. M., and Hanzlik, R. P. (1998) Chem. Res. Toxicol. 11, 178−184]. To identify protein targets for Bromobenzene metabolites in cytosol, we incubated liver microsomes and glutathione-depleted liver cytosol from phenobarbital-treated rats with [14C]Bromobenzene in vitro. In a separate experiment, we intraperitoneally injected a hepatotoxic dose of [14C]Bromobenzene to phenobarbital-treated rats. The cytosol fractions from both experiments were recovered and analyzed for protein-bound radioactivity. Under the conditions that were used, 2.6 and 3.9 nmolar equiv of Bromobenzene/mg of cytosolic protein was bound in vitro and in vivo, respectively. Denaturing polyacrylamide gel electrophoresis of these cytosolic p...
Charles Beromeo Bheeter - One of the best experts on this subject based on the ideXlab platform.
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Palladium-catalysed direct heteroarylation of Bromobenzenes bearing SO2R substituents at C2 or C4
RSC Advances, 2015Co-Authors: Charles Beromeo Bheeter, Rongwei Jin, Jitendra K. Bera, Henri DoucetAbstract:Palladium-catalysed direct arylation of 4- or 2-Bromobenzenesulfonic acid derivatives in the presence of a variety of heteroaromatics was found to proceed using 0.1-0.5 mol% palladium acetate as the catalyst. However, both the nature and position of the SO2R substituent on such Bromobenzenes has an influence on the reaction rates and yields. The presence of SO2Et or SO2NEt2 at the C2 or C4 position of Bromobenzene is tolerated. Good results were also obtained from Bromobenzene substituted at C4 by SO2NHPh or SO2OPh. On the other hand, the reactions of Bromobenzenes bearing either SO2N(Me)CH2Ph or SO2OAr at C2 led in some cases to intramolecular reactions instead of the desired intermolecular couplings. Some reactions were performed in cyclopentyl methyl ether, which can be considered as a green solvent.
Andrew D Kohler - One of the best experts on this subject based on the ideXlab platform.
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a strategy for isotope containment during radiosynthesis devolatilisation of Bromobenzene by fluorous tagging ir catalysed borylation en route to the 4 phenylpiperidine pharmacophore
Organic and Biomolecular Chemistry, 2008Co-Authors: Alan C Spivey, Laetitia J Martin, Chihchung Tseng, George J Ellames, Andrew D KohlerAbstract:Syntheses of two 4-phenylpiperidines from Bromobenzene have been developed involving anchoring to a fluorous-tag, Ir-catalysed borylation, Pd- and Co-catalysed elaboration then traceless cleavage. Although performed using ‘cold’ (i.e. unlabelled) Bromobenzene as the starting material, these routes have been designed to minimise material loss via volatile intermediates and expedite purification during radiosynthesis from ‘hot’ (i.e. [14C] labelled) Bromobenzene.
Janusz Serwatowski - One of the best experts on this subject based on the ideXlab platform.
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bromine as the ortho directing group in the aromatic metalation silylation of substituted Bromobenzenes
Journal of Organic Chemistry, 2003Co-Authors: Sergiusz Lulinski, Janusz SerwatowskiAbstract:The one-pot metalation/disilylation of selected Bromobenzenes bearing electron-withdrawing substituents p-, m-, o-XC6H4Br (X = F, Cl, I, CN, CF3) using 2 equiv of lithium diisopropylamide (LDA) and 2 equiv of chlorotrimethylsilane (TMSCl) was investigated. The best results of disilylation were obtained for para-substituted Bromobenzenes, but the regioselectivity of the reaction is strongly influenced by the ortho-directing power of the substituent. On the contrary, the disilylation of meta-substituted Bromobenzenes was not efficient or even failed in some cases and hence monosilylated derivatives were isolated as major or sole products. Diverse reactivity was observed for ortho-substituted Bromobenzenes, e.g., 2-bromobenzonitrile and 2-bromochlorobenzene, were converted into corresponding disilylated derivatives in a high and moderate yield, respectively, whereas 1-bromo-2-(trifluoromethyl)benzene underwent only monosilylation.
