Heterogeneous Photocatalytic Radical Synthesis of Aryl Allyl Sulfones

A photocatalytic synthesis of aryl allyl sulfones by a radical cascade reaction from an aryl diazonium salt, DABCO·(SO2)2 and 3-bromoprop-1-ene has been developed. This reaction employed ­DABCO·(SO2)2 as the SO2 source and a polyaniline–graphitic carbon ­nitride–titanium dioxide composite as the photocatalyst. A series of substrates were tolerated, providing the corresponding products in good yields. Moreover, the photocatalyst could be readily recovered and reused several times with only a slight decrease in its catalytic activity.