Site-selective carbonylation of arenes via C(sp2)-H thianthrenation: Palladium-catalyzed direct access to α,β-unsaturated ketones

Herein, an efficient palladium-catalyzed carbonylative Heck reaction of aryl thianthrenium salts with carbon monoxide and alkenes has been developed. This protocol can greatly reduce the quantity of olefins used in the carbonylative Heck reaction. In addition, the reaction can also proceed when the coupling partner is a non-activated olefin which is not common in such carbonylative Heck reactions. Combined with C–H thianthrenation of aromatic hydrocarbons, this work provides an efficient method for the site-selective C–H carbonylative Heck reaction of aromatic hydrocarbons. It may serve as a significant late-stage carbonylation tool for the modification of complex molecules in the future.