Palladium-Catalyzed Cascade Carbonylation Reaction: Synthesis of Fused Isoindolinones.

A palladium-catalyzed cascade carbonylation reaction of 2-bromo--(2-iodophenyl)benzamides with benzylidenecyclopropanes for the synthesis of fused isoindolinone derivatives has been developed. A broad range of 6/5/6/6 tetracyclic isoindolinone products were efficiently prepared in moderate to good yields with diverse substitution. Two carbonyl groups were incorporated into the substrates in a single step with the formation of four carbon-carbon bonds and two carbon-heteroatom bonds.