- Copper-Catalyzed Regioselective C-H Sulfonyloxylation of Electron-Rich Arenes with p-Toluenesulfonic Acid and Sulfonyloxylation of Aryl(mesityl)iodonium Sulfonates
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Copper-catalyzed regioselective C-H sulfonyloxylation of electron-rich arenes with p-toluenesulfonic acid has been developed. Electron-rich benzene derivatives and heteroarenes can undergo this C-H sulfonyloxylation reaction to generate aryl tosylates. Furthermore, sulfonyloxylation of aryl(mesityl)iodonium sulfonates has also been investigated. Both aryl(mesityl)iodonium tosylates and triflates can react smoothly to get aryl sulfonates. The formed aryl sulfonates can be converted to phenols, as well as used as good partners of cross-coupling reactions.
- Huang, He,Wu, Yang,Zhang, Wen,Feng, Chun,Wang, Bi-Qin,Cai, Wan-Fei,Hu, Ping,Zhao, Ke-Qing,Xiang, Shi-Kai
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p. 3094 - 3101
(2017/03/23)
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- Design, synthesis, and biological evaluation of aryloxyethyl thiocyanate derivatives against Trypanosoma cruzi
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As a continuation of our project aimed at the search for new and safe chemotherapeutic and chemoprophylactic agents against American trypanosomiasis (Chagas' disease), several drugs structurally related to 4-phenoxyphenoxyethyl thiocyanate (4) were designed, synthesized, and evaluated as antiproliferative agents against the parasite responsible for this disease, the hemoflagellated protozoan Trypanosoma cruzi. This thiocyanate derivative was previously shown to be an effective and potent agent against T. cruzi proliferation. Several drugs possessing thiocyanate groups proved to be effective growth inhibitors of T. cruzi growth. Among the designed compounds, it is important to point out the extremely potent activity shown by 11, 23, 38, 53, 90, 99, and 117 against the epimastigote forms of the parasite. All of them exhibited IC50 values in the low micromolar range, and these values were comparable with those presented by our lead drug 4 and ketokonazole, a well-known antiparasitic agent. The activity displayed by the nitrogen-containing derivative 90 was very promising with IC50 values of 3.3 μM. Several other thiocyanate derivatives also proved to be very potent inhibitors of the multiplication of T. cruzi epimastigotes, such as compounds 28, 33, 43, 48, 56, 61, 66, 71, 76, and 124. Compound 43 resulted in being a promising drug because it was also very effective against amastigotes, the clinically more relevant form of the parasite. This compound was 3-fold more potent than 4, while 11 showed nearly the same activity as our lead drug against intracellular T. cruzi. It was very surprising that the experimental juvenoid 124, although fairly devoid of activity against epimastigotes, was very effective against intracellular amastigotes growing in myoblasts. The rest of the designed compounds showed a broad degree of inhibitory action, from moderately active drugs to drugs almost devoid of antiparasitic activity. Compound 43 is an interesting example of an effective antichagasic agent that presents excellent prospectives not only as a lead drug but also to be used for further in vivo studies.
- Elhalem, Eleonora,Bailey, Brian N.,Docampo, Roberto,Ujváry, István,Szajnman, Sergio H.,Rodriguez, Juan B.
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p. 3984 - 3999
(2007/10/03)
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- Facile Deoxygenation of Phenols and Enols Using Sodium Borohydride-Nickel Chloride
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A facile deoxygenation reaction of phenol and 1,3-dicarbonyl compounds was investigated.Phenols, enolizable 1,3-diketones and 3-ketoesters were converted into the toluene-p-sulfonates which were reduced by a sodium borohydride-nickel chloride system to give the deoxygenated aromatic compounds, alcohols and esters, respectively.
- Wang, Feng,Chiba, Kazuhiro,Tada, Masahiro
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p. 1897 - 1900
(2007/10/02)
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