A metal‐free multi‐component sulfur dioxide insertion reaction of alkynes, sodium metabisulfite, aryldiazonium, and quinoxalin‐2‐ones has been developed under visible‐light photoredox‐catalysis. This photocatalytic tandem reaction would be conducted at room temperature by using of Rhodamine 6G as organic photocatalyst and sodium metabisulfite as the SO2 surrogate. This protocol provides a synthetic strategy for the construction of various quinoxalin‐2‐one‐containing vinyl sulfones with favourable functional group tolerance, in which one C−C bond and two C−S bonds were constructed in one pot procedure.

A visible-light photoredox-catalyzed four component reaction of quinoxalin-2(1H)-ones, alkenes, aryldiazonium, and sodium metabisulfite leading to sulfone-containing quinoxalin-2(1H)-ones has been developed.

The first catalytic vicinal thiosulfonylation and trifluoromethylthiosulfonylation of ynones have been developed. Under the catalysis of 1-20 mol% Cs2CO3, various ynones underwent Michael addition/nucleophilic substitution tandem reaction with different thiosulfonates...