One-pot chemoselective aerobic synthesis of allyl–aryl sulfinyls by photoinduced Na ₂ – eosin Y

Allyl-aryl sulfinyls are ubiquitous in medicine as well as in catalysis. Chemoselective synthesis of allyl-aryl sulfinyls is challenging due to competitive isomerization and overoxidation of allylic C-H bonds as well as sulfur. Herein, we have accomplished an unprecedented, metal-free, one-pot protocol for the aerobic synthesis of allyl-aryl sulfinyls from Morita-Baylis-Hillman allyl bromides and thiols under visible light photocatalysis through a radical pathway. Interestingly, this selective and controlled oxidation of <i>in situ</i>-formed allyl-aryl sulfides by the sub-stoichiometric oxidizing agent TEMPO <i>via</i> visible-light photocatalysis is well tolerated by an array of allyl bromides and thiols. This approach provides an efficient one-step route to the anti-cancer molecule INF₅₀, and its synthetic application is demonstrated by an interrupted Pummerer reaction.