An efficient, oxidant and photocatalyst-free approach for the synthesis of polycyclic-fused isoindolinone derivatives is reported via annulation of 3,4-diphenyl-3-pyrrolin-2-ones along with release of the hydrogen gas under an argon atmosphere in EtOH by irradiation with a 500 W mercury lamp at room temperature. The described approach is atom-economic and environmentally friendly and tolerates various