Palladium-catalyzed alkoxycarbonylation reactions of (E)-2-en-4-yne carbonates

Abstract

Transition metal-catalyzed carbon-carbon bond formation reactions are well-rounded methods to synthetic organic chemistry. One type of these reactions is the alkoxycarbonylation reactions performed in the presence of a transition metal catalyst, an alcohol and carbon monoxide atmosphere. Investigations on palladium-catalyzed alkoxycarbonylation reaction of allylic compounds leading to β,γ-unsaturated esters have been performed. Moreover propargyl derivatives are prominent reactants for palladium-catalyzed alkoxycarbonylation reactions to yield allene esters which proceed through a σ-allenylpalladium intermediate. Palladium-catalyzed alkoxycarbonylation reaction of some enantio-enriched propargylic derivatives that facilitate unique centre-to-axis chirality transfer is still inadequate and essential. In this study, the palladium-catalyzed alkoxycarbonylation reaction of E-configured 2,4-enyne carbonates which afforded exclusively ester functionalized (E)-configured vinylallenes through the formation of σ-vinylallenylpalladium species was performed. Moreover the chirality transfer of the proposed method was also surveyed over an enantio-enriched E-enyne carbonate.