Access to α,β-unsaturated carboxylic acids through water-soluble palladium catalyzed hydroxycarbonylation of alkynes using water as the solvent

A sulfoxantphos modified palladium-catalyzed synthesis of α,β-unsaturated carboxylic acids from alkynes with CO and H 2 O was described. The atom-economic hydroxycarbonylation of various symmetrical and unsymmetrical alkynes can be achieved with chemo-, stereo-, and regioselectivity, affording the corresponding carboxylic acids in good to excellent yields. Using water as the reaction solvent, the water-soluble palladium catalyst was easily separated from the product and could be reused for 5 cycles. A reusable water-soluble Pd(OAc) 2 /sulfoxantphos catalyst has been developed for the hydroxycarbonylation of symmetrical and unsymmetrical alkynes with CO/H 2 O to afford the corresponding α,β-unsaturated carboxylic acids in good yields.