Gold(I)-Catalyzed Intramolecular Carbon-Oxygen Bond Cleavage ReactionviaGold Carbenes Derived from Vinylidenecyclopropanes

Under gold(I) catalysis, the in situ generated gold carbene from vinylidenecyclopropanes bearing a methoxymethyl group can undergo an intramolecular nucleophilic attack to give the carbon-oxygen bond cleavage product in good yield within 15 min. and different phosphine ligands could control both Z- and E-configurations, respectively. The reaction mechanism has been clarified on the basis of deuterium- and 18O-labeling experiments. This method provides a new and efficient approach to stereoselectively synthesize alkylidenecyclobutanones under mild conditions.