Palladium‐Catalyzed CH Activation and Intermolecular Annulation with Allenes

Abstract A new and efficient Pd II ‐catalyzed intermolecular annulation of N ‐benzoylsulfonamide with allenes for the synthesis of 3,4‐dihydroisoquinolin‐1(2 H )‐ones is reported. This CH functionalization is compatible with ambient air and moisture, and it can be applied to terminal or internal allenes with different synthetically attractive functional groups. Control experiments and a kinetic isotope effect study are conducted and a plausible mechanism is proposed.