A method for the synthesis of sulfides from carboxylic acids via thioester C-S activation and acyl capture has been accomplished, wherein thioesters serve as dual electrophilic activators to carboxylic acids as well as S-nucleophiles through the merger of decarbonylative palladium catalysis and sulfur coupling. This new concept engages readily available carboxylic acids as coupling partners to directly intercept sulfur reagents via redox-neutral thioester-enabled cross-over thioetherification. The scope of this platform is demonstrated in the highly selective decarbonylative thioetherification of a variety of carboxylic acids and thioesters, including late-stage derivatization of pharmaceuticals and natural products. This method operates under mild, external base-free, operationally-practical conditions, providing a powerful new framework to unlock aryl electrophiles from carboxylic acids and bolster the reactivity by employing common building blocks in organic synthesis.