Ruthenium-Catalyzed Regio- and Stereoselective Addition of Carboxylic Acids to Aryl and Trifluoromethyl Group Substituted Unsymmetrical Internal Alkynes

The regio- and stereoselective addition of carboxylic acids to aryl and trifluoromethyl group substituted unsymmetrical Internal alkynes has been accomplished: the Ru-3(CO)(12)/3PPh(3) catalyst system has effectively catalyzed the reaction to afford the trifluoromethyl group substituted (E)-enol esters with high regio- and stereoselectivities.