Access to Substituted Carbazoles in Water by a One‐Pot Sequential Reaction of α,β‐Substituted Nitro Olefins with 2‐(3‐Formyl‐1H‐indol‐2‐yl)acetates

Abstract

AbstractA series of interesting new multifunctional carbazole scaffolds have been prepared in good to excellent yields by an organocatalytic one‐pot two‐step sequential reaction between α‐alkyl‐β‐substituted nitro olefins or α‐alkyl‐δ‐substituted nitro‐dienes and 2‐(3‐formyl‐1H‐indol‐2‐yl)acetates in water at room temperature followed by treatment with 2 n HCl under mild conditions. This one‐pot, organocatalytic, oxidant‐free, mild, and eco‐friendly process may provide a powerful alternative synthetic protocol to rapidly access 3‐alkyl‐substituted carbazole frameworks that have a close structural resemblance to biologically active natural carbazoles. Moreover, biologically significant cyclic imide‐ and quinolinone‐fused carbazoles have been efficiently prepared by using this synthetic method.