Ligand-Controlled Copper-Catalyzed Regiodivergent Sulfonylation of Yne-Vinyl Allylic Esters with Sodium Sulfinates

Herein, we report the first ligand-controlled copper-catalyzed regiodivergent sulfonylation of yne-vinyl allylic esters with sodium sulfinates. The practicality and attractiveness of this protocol are showcased using readily available starting materials, mild reaction conditions, good regio- and stereoselectivities, and a broad substrate scope. A series of controlled experiments identified a copper divinyl-allenylidene complex as the key intermediate in this reaction. Density functional theory calculations delineate distinct mechanistic pathways for each nucleophilic addition step and elucidate their regioselectivity.