While the reductive ketyl couplings of carbonyls have been widely explored, we report in this work on a redox-neutral umpolung carbonyl coupling reaction through ketyl radical formation by consecutive photoinduced...

The three-component reaction for the synthesis of 2-arylthiophenes has been developed. Easily available arylacetaldehydes, 1,3-dicarbonyls, and elemental sulfur were directly assembled through cascade condensation/ annulation under base conditions. The present protocol provides a facile entry to 2,3,5-trisubstituted thiophenes with moderate to excellent yields and good functional group tolerance.

A mild transition-metal- and photosensitizer-free photoredox system based on the combination of NaI and PPh3 was found to enable highly selective reduction of nitroarenes. This protocol tolerates a broad range of reducible functional groups such as halogen (Cl, Br, and even I), aldehyde, ketone, carboxyl, and cyano. Moreover, the photoredox catalysis with NaI and stoichiometric PPh3 provides also an alternative entry to Cadogan-type reductive amination when o-nitrobiarenes were used.

A cooperative base system has been developed for the novel three-component synthesis of 2-aminobenzo[4,5]thieno[3,2-d]thiazoles via bis-heterocyclization of methylketoxime acetates.

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