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

The chemoselective addition of arenes and 1,3‐diketones to α‐aryldiazoesters was achieved through ligand‐controlled gold catalysis. Unlike a dirhodium catalyst (which promotes C   sp   3H 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.