Direct construction of benzimidazo[l,2- c ]quinazolin-6-ones via metal-free oxidative C–C bond cleavage

A highly regioselective C–C bond cleavage/amination of isatins has been developed for the synthesis of benzimidazo[1,2- c ]quinazolin-6-ones by reacting with o -phenylene diamines. This practical transition-metal-free method is operationally simple, enabling the C–C bond cleavage and triple C–N bond formation, wherein molecular oxygen is the sole required oxidant.