Construction of Spiro[indoline-3,2′-pyrrolo[2,1-a]Isoquinoline] and Spiro[indoline-3,2′-pyrrolo[1,2-a]Quinoline] via Isocyanide-Based Three-Component Reaction

Abstract

A convenient synthetic protocol for novel spiro[indoline-3,2′-pyrrolo[2,1-a]isoquinoline] and spiro[indoline-3,2′-pyrrolo[1,2-a]quinoline] motifs was successfully developed by three-component reaction of isoquinoline (quinoline), cyclohexyl isocyanide, and isatylidene malononitriles. In the absence of any catalyst, the three-component reaction of isoquinoline, cyclohexyl isocyanide, and isatylidene malononitriles in refluxing dichloromethane gave functionalized spiro[indoline-3,2′-pyrrolo[2,1-a]isoquinolines] in good yields and with high diastereoselectivity. However, the similar three-component reaction with quinoline afforded functionalized spiro[indoline-3,2′-pyrrolo[1,2-a]quinolines] with about 2:1 diastereoselectivity.