Chemoselective Carbophilic Addition of α-Diazoesters through Ligand-Controlled Gold Catalysis

The chemoselective addition of arenes and 1,3-diketones to -aryldiazoesters was achieved through ligand-controlled gold catalysis. Unlike a dirhodium catalyst (which promotes Csp3H insertion and cyclopropanation) and a copper catalyst (which catalyzes OH and NH insertions), the gold catalyst with an electron-deficient phosphite as the ancillary ligand exclusively gave the carbophilic addition product, thus representing a new and efficient approach to form carbophilic carbocations, which selectively react with carbon nucleophiles.