En route towards "organic sodium": strongly excited-state reducing phenothiazines with application in photoredox catalysis.

The phenothiazine scaffold with a strongly electron-donating substituent is a suitable structural motif for the development of new photoredox catalysts operating in the oxidative quenching cycle. The design, investigation and application of new, highly reducing tri-substituted phenothiazines, which can be readily accessed in a one-pot procedure, reveal sodium-like oxidation potentials upon excitation with UV light.