Construction of Spiro[indeno[2,1‐ e ]pyrrolo[3,4‐ b ]pyridine‐10,3′‐indoline] and Indeno[1,2‐ b ]pyrrolo[3,4‐ e ]pyridine via Three‐Component Reaction

The three‐component reaction of β‐ enamino imides, isatins and indan‐1,3‐dione in refluxing ethanol in the presence of triethylamine afforded functionalized spiro[indeno[2,1‐ e ]pyrrolo[3,4‐ b ]pyridine‐10,3′‐indolines] in good yields. The similar three‐component reaction of β‐ enamino imides, aromatic aldehydes and indan‐1,3‐dione in methylene dichloride in the presence of boron trifluoride etherate resulted in the corresponding indeno[1,2‐ b ]pyrrolo[3,4‐ e ]pyridine derivatives.