Novel Substrates for Palladium-Catalyzed Coupling Reactions of Arenes

Arenes and heteroarenes are ubiquitous substructures in biologically active agents and new materials. Thus, functionalization (“refinement”) of simple arene precursors is still of major importance for preparative organic chemistry. During the last 20 years, especially transition‐metal‐catalyzed cross‐coupling reactions of aryl halides and triflates have given arene chemistry new impetus. The first industrial applications were realized a few years ago. Quite recently, carbonic acid derivatives such as anhydrides and esters have added to the scope of substrates for these coupling reactions. Some recent developments in this area are presented in this Minireview. Alternative coupling partners: Not only haloarenes, but also aryl carbonic acids and heteroaryl thioethers (see formulas) can take part in palladium‐catalyzed coupling reactions. The substrate scope has thus become broader and the catalyst systems simpler. Furthermore, the reaction of carbonic acid derivatives allows the simple synthesis of ketones.