Novel Stereospecific Synthesis of 3-Chloroacrylate Esters via Palladium-Catalyzed Carbonylation of Terminal Acetylenes

A simple and effective method for the highly regio- and stereospecific synthesis of (Z)-3-chloroacrylate esters is described. Using terminal acetylenes and primary, secondary, and tertiary aliphatic alcohols as substrates, the carbonylation reactions were carried out under carbon monoxide (1 atm) at room temperature in the presence of a catalytic amount of PdCl2 and 3 equiv of cupric chloride. Isolated yields of (Z)-3-chloroacrylate esters ranging from 30% to 72% were obtained. Our results show that the polarity of the alcohol−benzene solvent plays an important role in the stereochemistry of the products.