Rhodium catalyzed sequential dual C–H annulation of 3-arylisoxazoles with 1,6-diynes to access fused naphthalenes

Selective dual C-H annulations with 1,<i>n</i>-diunsaturated systems represent a powerful tool for constructing multicyclic scaffolds in an expeditious manner. Here, we report a rhodium catalyzed sequential dual C-H annulation of 3-arylisoxazoles with 1,6-diynes for napthofused polycyclic systems. Some kinetic isotopic experiments were carried out to understand the reaction mechanism and some downstream experiments were conducted to demonstrate the potential of the methodology. The method features a broad substrate scope and scale-up capability.