2,3-Allenoic acids via palladium-catalyzed carboxylation of propargylic alcohols

Abstract

A straightforward protocol for the synthesis of tetra-substituted 2,3-allenoic acids via a catalytic carboxylation of the readily available propargylic alcohols in the presence of CO using palladium and a Brønsted acid as the cocatalysts has been established. This atom-economical reaction proceeded under mild conditions to afford 2,3-allenoic acids with a broad scope tolerating useful functional groups.