Organotellurium Chemistry. 7. Reductive Removal of Electronegative α Substituents of Ketones and Acids by a Tellurolate Reagent

Article abstract of DOI:10.1021/jo00141a026

Lithium and sodium 2-thiophenetellurolates have been used for the reductive dehalogenation of a variety of α-halo ketones and acids.Acetoxy, mesyloxy, and phenylthio groups were also successfully removed from the α position of an acetophenone.The reductions could in many cases be carried out by using sodium borohydride as the reducing agent in the presence of only a catalytic amount of the organotellurium reagent.Evidence is presented in support of a two-step mechanism involving the formation of α-aryltelluro carbonyl derivatives and enolate anions in succession.