LAUSR

Abstract An expedient method for the synthesis of cyclic carbonates from homoallylic carbonic acid esters by means of photo‐aerobic selenium‐π‐acid multicatalysis is reported. Until now, conceptually related methods commonly relied either on the stoichiometric addition of electrophiles onto the substrate's alkene moiety or the presence of pre‐installed leaving groups in allylic position of said alkene to – in part, catalytically – initiate an intramolecular attack by an adjacent carbonic acid ester group. In sharp contrast, the current study shows that the C−C double bond of homoallylic carbonic acid esters can be directly activated by the catalytic interplay of a pyrylium dye and a diselane using ambient air as the sole oxidant and visible light as an energy source.