Visible-Light-Induced Arene C(sp (2) )-H Lactonization Promoted by DDQ and tert -Butyl Nitrite

A visible-light photocatalytic aerobic oxidative lactonization of arene C(sp (2) )-H bonds proceeds in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tert -butyl nitrite (TBN). Under the optimized conditions, a range of 2-arylbenzoic acids is converted into the corresponding benzocoumarin derivatives in moderate to excellent yields. This method is characterized by its atom economy, mild reaction conditions, the use of a green oxidant and metal-free catalysis.