Pd-Catalyzed Carbonylative Reactions of Aryl Iodides and Alkynyl Carboxylic Acids via Decarboxylative Couplings

Alkynyl carboxylic acids reacted with aryl iodides under a CO atmosphere in the presence of a palladium catalyst to produce alpha,beta-alkynyl aryl ketones in good yields. The maximum turnover number was 16800. The desired carbonylative coupling was formed from phenyl propiolic acid without any formation of a noncarbonylative coupling product in the absence of Cul. However, the reaction with alkyl-substituted alkynyl carboxylic acids required Cul as a cocatalyst for high yield.