beta,gamma,-Unsaturated ketones are an important class of organic molecules. Herein, copper catalysis has been developed for the synthesis of --unsaturated ketones through 1,2-addition of -carbonyl iodides to alkynes. The reactions exhibit wide substrate scope and high functional group tolerance. The reaction products are versatile synthetic intermediates to complex small molecules. The method was applied for the formal synthesis of (+/-)-trichostatinA, a histone deacetylase inhibitor.