Transition-Metal-Free C‑3 Arylation of Quinoline-4-ones with Arylhydrazines

A transition-metal-free C-3-arylation
of quinolin-4-ones in the
presence of base has been achieved by using arylhydrazines as aryl
radical source and air as oxidant. The reaction proceeds smoothly
at room temperature and does not require any prefunctionalization
and N-protection of quinoline-4-ones. The utility
of this methodology is further demonstrated in synthesis of quinoline–quinolone
hybrid as well as 6-aryl-benzofuro­[3,2-c]­quinoline
scaffold.