Synthesis of Lactams via a Chiral Phosphoric Acid-Catalyzed Aniline Cyclization.

The enantioenriched lactams disclosed in this work are synthesized concisely in four steps. In the penultimate reaction, a benzylamine species complexes with a chiral phosphoric acid to produce benzo-fused δ-lactams equipped with an all-carbon quaternary stereocenter. Partial and full reductions were carried out on the ester and amide moieties, and a Suzuki-Miyaura cross-coupling expanded the molecule from the aromatic ring.