Pd/Cu-catalyzed oxidation of alkynes into 1,2-diketones using DMSO as the oxidant

A facile and practical method for the palladium/copper-catalyzed transformation of internal alkynes into 1,2-diketones has been described, affording the desired products in moderate to excellent yields. The mechanistic studies were also preliminarily pursued using diphenyl sulfoxide as the oxidant, and the diphenyl sulfide was isolated as the reduced product.