Pd-catalyzed synthesis of functionalized arylketones from boronic acids and carboxylic acids activated in situ with dimethyl dicarbonate

Highly efficient catalyst systems were developed that allow the palladium-catalyzed cross-coupling of arylboronic acids with carboxylic acids activated in situ with dimethyl dicarbonate at room temperature. As byproducts, only methanol, CO2, and boric acid are formed, making the isolation of the products particularly easy. Thus, many functionalized ketones are conveniently accessible from boronic and carboxylic acids in the presence of 1.5 equivalents of dimethyl dicarbonate and Pd(OAc)(2)-P(p-MeOPh)(3) as the catalyst, The presence of small amounts of water and a ligand-Pd ratio lower than 4 is crucial for achieving good yields at low temperatures.