Porphyrin-Catalyzed Oxidation Of N-Substituted Tetrahydroisoquinolines To Dihydroisoquinolones

A visible-light-induced direct alpha-oxygenation of N-substituted 1,2,3,4-tetrahydroisoquinoline derivatives has been successfully developed. Tetraphenylporphyrinatozinc(II) has been identified as an effective and inexpensive photocatalyst for this transformation with a wide range of substrates. This protocol provides a convenient route to the desired products in moderate to good yields at room temperature under air.