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 synt hesis of (Z)-3-chloroacrylate esters is described. Using terminal acetylene s and primary, secondary, and tertiary aliphatic alcohols as substrates, th e carbonylation reactions were carried out under carbon monoxide (1 atm) at room temperature in the presence of a catalytic amount of PdCl2 and 3 equi v of cupric chloride. Isolated yields of (Z)-3-chloroacrylate esters rangin g 6 om 30% to 72% were obtained. Our results show that the polarity of the alcohol-benzene solvent plays an important role in the stereochemistry of t he products.