Vinyltriphenylphosphonium salt-mediated preparation of thiophene-containing electron-poor alkenes from acetylenic esters, 2-thienylmethanol and triphenylphosphine

چکیده مقاله

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and alkyl acetylenecarboxylates (methyl acetylenecarboxylate, ethyl acetylenecarboxylate and ethyl phenylacetylenecarboxylate) by 2-thienylmethanol leads to vinyltriphenylphosphonium salts, which undergo an addition-elimination reaction in CH₂Cl₂ at room temperature to produce the corresponding O-vinylated alkenes via thiophene-containing phosphorus ylides intermediates in fairly high yields. The structural analysis of all products indicated that the reactions are regio- and stereoselective. © 2011 Chemical Society of Ethiopia.