Synthesis of fused rings at a pivotal nitrogen: tandem Heck reactions of N-vinyl-2-iodobenzamides

A short two-step synthesis of the tetracyclic nitrogen heterocycles 2 (isoindoloneindole, isoindoloneisoquinoline and isoindolone[3]benzazepine) is presented. Condensation of the corresponding o-bromoarylamine with acetaldehyde followed by acylation with o-iodobenzoyl chloride affords the key dihalo N-vinylbenzamides 1, which are then cyclized by a tandem Heck reaction.