Palladium-Catalyzed Regio- and Stereoselective C–H Alkynylation of Conjugated Dienols

The regioselective activation of alkenyl C-H bonds in conjugated dienols presents significant challenges due to the presence of multiple similarly reactive sites. In this study, we developed a palladium-catalyzed alkynylation method that is both regio- and stereoselective for the activation of internal alkenyl C-H bonds. This approach provides an efficient and versatile strategy for synthesizing dienyne derivatives with precise <i>Z</i> and <i>E</i> configurations. Stereocontrol is achieved through the introduction of acetate salts, which effectively modulate the reaction pathway, allowing for selective outcomes via either a C-H activation process or a Heck coupling mechanism. This innovative strategy not only enhances the specificity of the synthesis but also broadens the potential applications of the resulting dienyne derivatives in various fields.