Pd-Catalyzed Dehydrogenative Aryl−Aryl Bond Formation via Double C(sp2)−H Bond Activation: Efficient Synthesis of [3,4]-Fused Oxindoles

A Pd(0)-catalyzed double cyclization of easily available o-bromoanilides leading to strained [3,4]-fused oxindoles was developed. The reaction proceeded through a highly ordered sequence involving key carbopalladation, 1,4-Pd migration, and C(sp2)−H functionalization steps.