One-pot chemoselective aerobic synthesis of allyl–aryl sulfinyls by photoinduced Na2 – eosin Y

Abstract

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 in situ-formed allyl–aryl sulfides by the sub-stoichiometric oxidizing agent TEMPO via 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.