Photoredox/Copper-Catalyzed Enantioselective S-Alkylation of Sulfenamides with Hydrocarbons Enabled by Commercial BOX Ligands

Enantioenriched sulfilimines are valuable sulfur-stereogenic building blocks, but catalytic asymmetric S-alkylation directly from hydrocarbons is still challenging. Here we report a dual photoredox/copper-catalyzed enantioselective S-alkylation of N-acyl sulfenamides with hydrocarbons enabled by commercially available chiral bis(oxazoline) (BOX) ligands. The reaction merges peroxide-based HAT with chiral copper catalysis to furnish sulfur-stereogenic sulfilimines from benzylic hydrocarbons and representative unactivated alkanes in good yields and enantioselectivities (up to 90% ee). A practical feature is that the hydrocarbon coupling partner is typically used in only 10 equivalents, improving substrate economy compared with related radical C(sp 3 )–H functionalizations. Stern–Volmer studies show efficient quenching of the photocatalyst by a copper/BOX/sulfenamide assembly, consistent with a cooperative initiation pathway.