Activation of Dioxygen in Air by a Phenol/Selectfluor System: An Application in the Oxidation‐Dimerization of Alkynes to 2‐Ene‐1,4‐diones

Activation of dioxygen in air by a combined phenol/Selectfluor system has been revealed. This technique has been exploited to develop an approach to 2-ene-1,4-diones via an oxidation-dimerization of alkynes under metal-free conditions.