Visible-Light-Catalyzed Ring-Opening Alkynylsulfonylation and Vinylsulfonylation of <i>Spiro</i> -Dihydroquinazolinones Enabled by Three-Component Insertion of Sulfur Dioxide

We develop a photoredox-catalyzed three-component deconstructive alkynylsulfonylation and vinylsulfonylation reaction of <i>spiro</i>-dihydroquinazolinones with alkynyl or vinyl halides and DABSO through the insertion of sulfur dioxide, providing the alkynyl and vinyl sulfones in generally good yields. Notably, this photocatalytic system can be expanded to synthesize relevant alkynylated and alkenylated quinazolinones when the reaction is conducted in the absence of DABSO under the standard conditions. More importantly, the resulting alkynyl sulfones were found to exhibit typical aggregation-induced emission properties in the mixture of THF/H₂O and could be applied to copper catalyzed [3 + 2] cycloaddition, establishing a versatile strategy for synthesizing a triazole unit and sulfonyl group-anchored quinazolinones.