Reaction of Acetophenone Hydrazones with TeCl₄: Novel Formation of 2,5-Diaryltellurophenes and Benzotellurophenes

Abstract

Reaction of acetophenone hydrazones with TeCl4 in the presence of DBU in CH2Cl2 at rt gave vinyl ditellurides and tellurides, whereas 2,5-diaryltellurophenes were obtained in refluxing DMF. Interestingly, when 1,2-diphenylethanone hydrazone was used as the substrate, 3-phenylbenzotellurophene was obtained in 45% yield. The reaction would proceed through telluroketone intermediates.