Visible-Light Photoredox Catalyzed Oxidative/Reductive Cyclization Reaction of <i>N</i>‑Cyanamide Alkenes for the Synthesis of Sulfonated Quinazolinones

An efficient photocatalytic oxidative/reductive cyclization reaction of <i>N</i>-cyanamide alkenes with arylsulfinic acids or arylsulfonyl chlorides, which proceeds through C–S, C–C, and C–N bond formations, is reported. This photocatalytic reaction was carried out under mild conditions, which provides a new strategy for the synthesis of sulfonated quinazolinones. Furthermore, a one-pot procedure to achieve terminal alkenes has been explored via elimination of the obtained sulfonated quinazolinones under basic conditions