Visible-light-induced direct C–N coupling of benzofurans and thiophenes with diarylsulfonimides promoted by DDQ and TBN

A visible-light-induced direct imidation of five-membered heteroaromatics with diarylsulfonimides via CDC reaction in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)/tert-butyl nitrite (TBN)/O2 is reported. Under the optimized conditions, various benzofurans/thiophenes can be coupled with a range of diarylsulfonimides to give their corresponding imidation products in moderate to excellent yields. This method is characterized by mild reaction conditions, metal-free catalysis and the use of a green oxidant.