A mild and convenient visible-light-induced method has been developed for the construction of 3-sulfonyl and 3-sulfenyl azaspiro[4,5]trienones through metal-free difunctionalization of alkynes with sulfinic acids or thiols at room temperature. The present protocol simply utilizes visible light as the safe and eco-friendly energy source, and inexpensive and non-toxic organic dyes (Eosin Y and Na₂-Eosin Y) as photocatalysts providing various sulfur-containing azaspiro[4,5]trienones in moderate to good yields.

A facile and efficient visible-light-driven method has been developed to construct sulfoxides via oxidative coupling of aryldiazo sulfones with thiols using the O₂ in air as the oxidant. This reaction could be performed at room temperature under catalyst- and additive-free conditions. The present methodology offers a mild and environmentally benign approach to obtain a library of sulfoxides in good yields with favorable functional group tolerance.

A selective synthesis of sulfoxides from alkenes and thiols was established by visible-light photoredox catalysis in air at room temperature.

A mild and facile visible-light-mediated strategy has been proposed for the synthesis of 3-acyl quinoxalin-2(1H)-ones through acridine red catalyzed aerobic oxidative decarboxylative acylation of α-oxo-carboxylic acids with quinoxalin-2(1H)-ones at room temperature in air. Various 3-acyl quinoxalin-2(1H)-ones could be efficiently obtained in good yields with excellent functional group compatibility.