Pd-Catalyzed Cascade Heck/C(sp)-H Activation for Spirocyclopropyl Oxindoles.

We have demonstrated a Pd(0)-catalyzed Heck/C(sp)-H activation cascade for the synthesis of spirocyclopropyl oxindoles in high yields from easily accessible -bromoacrylamides. The formation of spirocyclopropyl oxindole is guided by an unconventional four-membered palladacycle through C(sp)-H activation. The reaction exhibits a wide range of substrate scope and operates efficiently with a mere 0.