Copper‐Catalyzed CC Coupling of Thiol Esters and Boronic Acids under Aerobic Conditions

Getting rid of palladium: Thiol esters can be cross-coupled with boronic acids to generate ketones at neutral pH by using a CuI-oxygenate catalyst under aerobic and Pd-free conditions (see scheme; S-pendant=NHtBu thiosalicyclamide). The mechanistically unique coupling is likely to proceed by a preorganized, higher oxidation state Cu species that relies on appropriately positioned ligating S-pendant groups on the thiol ester and on an additional equivalent of the boronic acid.