Direct S0 → Tn Transition under Visible Light Irradiation Enabling Synthesis of a Pseudoindoxyl Scaffold.

Pseudoindoxyl is a partial skeleton found in various natural products. Its light-absorption properties make it useful for the design of functional molecules. However, versatile synthesis methods have not yet been reported. In this report, we present a versatile synthetic method for pseudoindoxyls using the direct S0 → Tn transition under visible light irradiation. We also discuss the application of pseudoindoxyls as photocatalysts.