Visible light-promoted synthesis of 4-(sulfonylmethyl)isoquinoline-1,3(2H,4H)-diones via a tandem radical cyclization and sulfonylation reaction.

Heterocyclic derivatives 4-(sulfonylmethyl)isoquinoline-1,3(2H,4H)-diones were synthesized via a visible-light-promoted reaction of N-alkyl-N-methacryloyl benzamides with sulfonyl chlorides catalyzed by fac-Ir(ppy)3 at room temperature. With various substituents on the substrates, the reaction proceeded smoothly to give the corresponding products in good to excellent yields. The products could be converted into 3-hydroxy-4-(sulfonylmethyl)-3,4-dihydroisoquinolin-1(2H)-one derivatives by the reduction of NaBH4.