A synthesis of spiroindolinone-isoindolinone skeletons is presented. The protocol is through a Ugi four-component reaction followed by highly efficient and mild copper-catalyzed intramolecular tandem CÀ N/ CÀ C coupling process. Control experiments demonstrated that the formation of CÀ C bond is a copper catalyzed coupling process rather than base promoted nucleophilic aromatic substitution pathway which proposed in Prof. Van der Eycken's palladium catalyst system previously.

An alkyne–isocyanide [3 + 2] cycloaddition followed by a Boulton–Katritzky rearrangement and a ring expansion is demonstrated. Different from the typical Boulton-Katritzky rearrangement, which forms five-membered ring products, the rearrangement-ring expansion method provides a mild, efficient, and atom-economical access to fused 9-deazaguanine structures in high yields.