Photoredox - catalyzed radical triggered tandem cyclization of o-hydroxyarylenaminones to access C3- substituted chromones

Abstract

A straightforward and novel synthetic route featuring tandem cyclization of o- hydroxyarylenaminones with in situ generated α-amino alkyl radicals has been developed. This work demonstrates a new visible-light induced cascade pathway for the construction of a variety C3- substituted 4H-chromen-4-ones using an organic photoredox catalyst, Eosin Y. Notably, this protocol afforded the C-3 functionalized 4H- chromen-4-ones in moderate to good yields under mild reaction conditions.