Wacker-Type Oxidation of Alkynes into 1,2-Diketones Using Molecular Oxygen

An intriguing new Wacker-type oxidation of alkynes catalyzed by PdBr2 and CuBr2 is described, which opens an efficient access to 1,2-diketones using molecular oxygen. Under the optimized conditions, a variety of alkynes, including diarylalkynes, arylalkylalkynes, and dialkylalkynes, were compatible substrates in this transformation. The mechanism of this reaction was preliminarily investigated by control experiments.