Electrophilicity of alpha-oxo gold carbene intermediates: halogen abstractions from halogenated solvents leading to the formation of chloro/bromomethyl ketones

alpha-Oxo gold carbenes generated via intermolecular oxidation of terminal alkynes are shown to be highly electrophilic and can effectively abstract halogen from halogenated solvents such as 1,2-dichloroethane or 1,2-dibromoethane. Chloro/bromomethyl ketones are prepared in moderate efficiencies in one step using Ph3PAuNTf2 as the catalyst and 8-methylquinoline N-oxide as the oxidant.