Cu-Catalyzed Stereoconvergent and Enantioselective C–S Cross-Coupling of Alkenyl Halides with Sulfenamides via Alkenyl Radicals

Transition-metal-catalyzed cross-coupling is a central strategy for installing alkenyl groups. Conventional two-electron oxidative addition of alkenyl halides is typically stereoretentive and, therefore, often requires geometrically highly enriched (E)- or (Z)-alkenyl halides, making stereoconvergent asymmetric cross-coupling of (E/Z)-mixed feedstocks challenging. Here we report a stereoconvergent and enantioselective Cu-catalyzed C-S cross-coupling of alkenyl iodides and bromides with sulfenamides to afford S-chiral alkenyl sulfilimines via alkenyl-radical intermediates that erase the initial alkene geometric information. The reaction proceeds under visible-light-driven Cu/photoredox conditions or Cu-catalyzed aryl radical-mediated halogen-atom transfer (XAT) conditions, delivering enantioenriched products with high alkene stereoselectivity and enantioselectivity across a broad substrate scope. The method is scalable, and the resulting chiral alkenyl sulfilimines can be readily diversified into a range of S-chiral sulfur(VI)-containing motifs, providing modular access to otherwise difficult-to-access enantioenriched sulfur-stereogenic alkenyl scaffolds.