Pd/Cu-Catalyzed Synthesis of Internal and Sila-Ynones by Direct Selective Acyl Sonogashira Cross-Coupling of Carboxylic Acids with Terminal Alkynes

The direct acyl Sonogashira cross-coupling of carboxylic acids with terminal alkynes has been achieved through Pd/Cu cooperative catalysis. In this reaction, the readily available carboxylic acids act as the acyl source for the coupling with various terminal alkynes to produce highly valuable ynones in good to high yields. The reaction features high chemoselectivity and functional group tolerance. The reaction offers access to versatile silyl-ynones. The late-stage modification of bioactive molecules and gram-scale experiments highlight the synthetic value of this reaction in organic synthesis. The method enables preparation of ynones directly from carboxylic acids in the absence of C(acyl)-C(sp) decarbonylation.