Decarboxylative Alkynylation of α-Keto Acids and Oxamic Acids in Aqueous Media.

A mild K2S2O8 promoted decarboxylative alkynylation of α-keto acids and oxamic acids has been developed. This process features mild reaction conditions, a broad substrate scope, and good functional-group tolerance, therefore providing a new and efficient access to a wide range of ynones and propiolamides. Furthermore, this radical process could also be successfully applied to alkynylation of the Csp2–H bond in DMF with hypervalent alkynyl iodide reagents.