Palladium-Catalyzed Difluorocarbene Transfer Enables Carbonylative Esterification of Aryl Thianthrenium Salts.

Aryl thianthrenium salt-mediated late-stage C-H carbonylation exhibits unique advantages in the site-selective modification of complex molecules. Herein, we disclose a palladium-catalyzed carbonylative esterification of aryl thianthrenium salts, in which commercially available potassium bromodifluoroacetate (BrCF2CO2K) is utilized as a safe and efficient CO surrogate. Carbon monoxide can be conveniently generated in situ via the reaction of the Pd(II)-difluorocarbene intermediate with water. This protocol features mild reaction conditions, low-cost and easily accessible raw materials, and high operational safety. It also possesses excellent functional group tolerance, thus serving as a practical strategy for the synthesis of high-value aromatic esters.