Concise Synthesis of Spiro[indoline‐3,2′‐pyrrolidine] and 1‐Azacarbazole Derivatives via Copper‐Catalyzed Cyclization of Indoles

A high-yielding copper-catalyzed dearomatization reaction of indole from 2-methyl indole-derived oxime acetates was realized, providing access to structurally novel spiro[indoline-3,2’-pyrrolidine] derivatives in 67-98% yields. When the C2-position of the indole was not substituted, aza-carbazole derivatives were obtained in moderate yields. This transformation provided an efficient approach to access nitrogen-containing spiroindolenine and aza-carbazole derivatives with wide substrate scope.