Gold-Catalyzed Intermolecular Oxidation of Terminal Alkynes: Simple and Efficient Synthesis of α-Mesyloxy Ketones

A variety of terminal alkynes were efficiently converted into the corresponding alpha-mesyloxy ketones through gold-catalyzed intermolecular oxidation in the presence of 3,5-dichloropyridine N-oxide as the oxidant. The reaction is proposed to proceed via alpha-oxo gold carbene intermolecular O-H insertion.