N-substituted-3(10H)-acridones as visible-light photosensitizers for organic photoredox catalysis.

N-Substituted-3(10H)-acridones have been established as visible-light organic photocatalyst. These photosensitizers are efficient for oxidative coupling reaction of N-aryl tetrahydroisoquinolines with various nucleophiles. Notably, N-methyl-3(10H)-acridone ( Ia ) is stable and can be effectively prepared. It is a water-soluble and atom-economic catalyst, and thus holds promise for green chemical applications. Mechanistic studies confirm a single electron transfer (SET)-induced radical process and a rate-limiting step. Analysis of the photocatalytic reactivity−structure relationship reveals that the acridones are robust and tunable photosensitizers for photoredox catalysis. [ABSTRACT FROM AUTHOR]