Synthesis of 2-substituted 1-benzyl-2,3,4,5-tetrahydro-1-benzazepines by palladium catalysis. Observation of a competitive β-hydride elimination pathway

A synthetic route to 1-benzyl-tetrahydro-1-benzazepine is reported, which also permits access to analogous structures with alkyl and aryl substituents at position-2 of the aliphatic ring. Palladium catalysis is utilized in two of the three steps, constructing the seven-membered rings effectively from 2-bromoiodobenzene. Competitive β-hydride elimination was observed in the attempted carbonnitrogen bond formation with a sterically bulky substrate (when R=tert-butyl).