Novel Synthesis of Benzenepolycarboxylates by Ruthenium-Catalyzed Cross-Benzannulation of Acetylenedicarboxylates with Allylic Compounds

Abstract

A catalyst system consisting of Cp*RuCl(cod)/PPh 3 [Cp* = pentamethylcyclopentadienyl, cod = 1,5-cyclooctadiene] for the novel cross-benzannulation of 2 equiv of dialkyl acetylenedicarboxylate with an allylic compound has been developed. As an example, the reaction of dimethyl acetylenedicarboxylate with allyl alcohol in the presence of 4 mol % Cp*RuCl(cod) and PPh 3 under reflux in toluene for 5 h gave tetramethyl 5-methyl-1,2,3,4-benzenetetracarboxylate in an isolated yield of 84%.