Synthesis of phenanthridine and its analogues via aerobic ligand-free domino Suzuki coupling–Michael addition reaction catalyzed by in situ generated palladium-nanoparticles in water

A convenient methodology has been developed towards the synthesis of substituted phenanthridines and analogous benzo[k] and benzo[i] derivatives via aerobic ligand-free domino Suzuki coupling–Michael addition reaction in the presence of Pd(OAc)2 and K3PO4 as a catalytic system in H2O at 90 °C in good yields. Reaction was believed to be catalyzed by in situ generated palladium nanoparticles in water with the elimination of acetone.