Free radical telluroacylative addition of telluroesters to terminal alkynes

Vinyl selenides and tellurides are important precursors of many kinds of organic compounds, particular the substituted alkenes that occurred in many biologically active compounds as skeleton structures. Thus the study of vinyl selenides and tellurides has attracted considerable attention in recent years. The bifunctional addition reactions involving selenium and tellurium moieties are the latest methods for preparation of vinyl selenides with various functional groups. Recently we have reported the selenocarbonylation of alkynes with selenoesters catalyzed by cuprous halides. Nevertheless the similar bifunctional addition involving tellurium atoms has not been reported. Considering the C-Te bonds are easier to be broken than corresponding C-Se bonds, the vinyl tellurides containing electron-withdrawing groups may have particular reactivity and application in the preparation of substituted alkenes. Herein we describe the synthesis of β-aryltelluro-α,β-unsaturated ketones via bifunctional addition.