Facile Assembly of Benzo[b]naphtho[2,3‐d]azocin‐6(5 H)‐ones by a Palladium‐Catalyzed Double Carbometalation

The palladium-catalyzed reaction of 2-alkynylanilines with 2-(2-bromobenzylidene)cyclobutanone as an efficient route to 7,8-dihydrobenzo[b]naphtho[2,3-d]azocin-6(5 H)-ones was developed. The fused eight-membered ring was constructed conveniently. During the reaction process, double carbometalation was involved, which resulted in excellent selectivity with the formation of three new bonds. This transformation is highly efficient and leads to fused polycycles in good to excellent yields with good functional group tolerance.