Generation of sulfonated isobenzofuran-1(3H)-ones under photocatalysis through the insertion of sulfur dioxide

Generation of sulfonated isobenzofuran-1(3H)-ones starting from 2-vinylbenzoic acids, aryldiazonium tetrafluoroborates, and sulfur dioxide surrogate of DABCO(SO2)(2) under photocatalysis in the presence of visible light is achieved. The presence of a photocatalyst assists the single electron transfer during the reaction process, thus facilitating the formation of desired products in good yields. Additionally, the method can be extended to 4-phenylpent-4-enoic acid and 5-phenylhex-5-enoic acid.