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

An efficient photocatalytic oxidative/reductive cyclization reaction of N-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.