Metal-Free Visible-Light-Mediated Desulfurization and Aromatization of Dihydropyrimidine-2-thiones for Synthesis of 2-Unsubstituted Pyrimidines.

The visible-light-mediated aerobic desulfurization and aromatization of Biginelli 3,4-dihydropyrimidine-2(1H)-thiones for a onestep synthesis of 2-unsubstituted pyrimidines was established. The protocol uses molecular oxygen as an inexpensive oxidant, with visible-light irradiation, and eosin B as an organophotoredox catalyst. [ABSTRACT FROM AUTHOR]