Base-Mediated Substrate-Dependent [2 + 3] and [3 + 3] Annulation of Bisnucleophiles: Enabling the Modular Synthesis of Functionalized Spirocyclopentane Oxindoles and Tetrahydro-α-carbolines.

Herein, we represented two facile and efficient approaches for the synthesis of functionalized spirocyclopentane oxindoles and tetrahydro-α-carbolines from different bisnucleophiles with 3-iodo-2-iodomethyl-1-propene via [2 + 3] and [3 + 3] annulation. These methods exhibit good functional group tolerances, simple conditions, easily available start materials, and moderate to good yields.