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Synthesis Of1,2,3-Triazoles Based On Organic-selenium Reagents

Posted on:2014-05-29Degree:MasterType:Thesis
Country:ChinaCandidate:W S ShengFull Text:PDF
GTID:2251330401487689Subject:Organic Chemistry
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1,2,3-Triazoles are one of the most useful heterocycles and have been widelyused in many research fields such as materials, chemical and biological sciences.Since Meldal and Sharpless developed the copper-catalyzed Huisgen’s1,3-dipolarcycloaddition reaction of azides with alkynes,‘click chemistry’ has receivedgrowing interest in the regioselective synthesis of1,4-disubstituted1,2,3-triazoles.Multi-component reactions (MCRs) are one of the most useful synthetic methodsbecause they allow rapid and convergent construction of complex molecules withoutthe isolation of intermediates. research according to the following two facts:(1)1-(2-phenylselenocyclohexyl)-4-substituted-1,2,3-triazoles:An efficient, one-pot, three-step, regioselective synthesis of4-substituted1-(2-phenylselenocyclohexyl)-1,2,3-triazoles involving in situ generation ofl-azido-2-phenylselenocyclohexane has been developed via four-component reactionof phenylselenenyl bromide, cyclohexene, sodium azide,40mol%DIPEA andterminal alkynes catalyzed by copper iodide(CuI;10mol%) in a mixture ofDMF/THF (1:1) at room temperature under mild conditions with simple workup andgood yields(83%-90%).(2)1-(E)-Phenylethenyl-4-substituted-1,2,3-triazole:Synthsis of1,4-disubstituted1,2,3-triazoles bearing1-(E)-phenylethenylgroup from phenylselenenyl bromide, cyclohexene, sodium azide afford2-azido-1-phenyl-1-(phenylseleno)ethane, and which treated with phenylacetylene inCH3CN/H2O (4:1) at room temperature for10h in the presence of triethylamine,followed by the addition excess of30%hydrogen peroxide by tandem reaction. Thebest yields is95%.
Keywords/Search Tags:Organic selenium, 1-(2-Phenylselenocyclohexyl)-4-substituted-1,2,3-triazoles, 1-(E)-Phenylethenyl-4-substituted-1,3-triazole, Huisgen’s1,3-dipolarcycloaddition, Multi-component tandem reactions (MCTRs)
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