Organophotocatalytic Oxidative Annulation of Phosphoryl Arylhydrazones to Access Indazoles

The present work documents organophotocatalytic transformation of N-phosphorylated arylhydrazones into indazoles. The strategy relies on the visible light-mediated generation of N-centered radical intermediate. The reaction employs organic dye as a photocatalyst and air as a terminal oxidant. The mild conditions, operational simplicity and fairly general scope are the notable attributes of the methodology.