Desulfitative Carbon–Carbon Cross‐Coupling of Thioamide Fragments with Boronic Acids

A novel and general carbon–carbon cross‐coupling reaction between cyclic thioamides and boronic acids is described. The reaction is catalytic in palladium(0) and requires stoichiometric amounts of a copper( I ) carboxylate as metal cofactor. The mode of cross‐coupling in the reaction of cyclic thioamides with boronic acids is easily tunable between carbon–carbon and carbon–sulfur cross‐coupling. While the catalytic palladium(0)/copper( I ) system provides carbon–carbon bond formation with extrusion of sulfur, stoichiometric quantities of copper( II ) under air mediate carbon–sulfur bond formation.