A Novel Olefination of Carbonyl Compounds with Dibromomalonate Promoted by Dibutyl Telluride

α,β-Unstaturated malonic esters are conveniently synthesized from the reaction of dibromomalonate with carbonyl compounds promoted by dibutyl telluride in exellent yields. A possible mechanism involving twice halophilic attacks of dibutyl telluride is proposed. This methodology provides a facile route to α,β-unsaturated malonic esters and represents an alternative to the Knoevenagel reaction.