Metal‐ and Solvent‐Free Synthesis of Maleimide Fused Carbazoles from (Indol‐3‐Yl)cyclohexanones and Maleimides
Fang Fang, Haolin Zheng, Weipeng Li, Guojiang Mao, Shanping Chen, Guo‐Jun Deng
Abstract
Abstract A metal‐ and solvent‐free strategy for the preparation of maleimide‐fused carbazoles has been developed. This protocol started from 2‐(indol‐3‐yl)cyclohexanones and maleimides, providing various maleimide‐fused carbazoles in 45–90% yields. The present approach was catalyzed by trimethylsulfoxonium iodide and involved a cascade of oxidation, [4+2] annulation, and dehydrogenative aromatization. Moreover, these maleimide‐fused carbazole products could be further transformed into other polycyclic aromatic hydrocarbons. magnified image
Topics & Concepts
MaleimideChemistryAromatizationCarbazoleAnnulationSolventIodideOrganic chemistryCatalysisCatalytic C–H Functionalization MethodsPhenothiazines and Benzothiazines Synthesis and ActivitiesMulticomponent Synthesis of Heterocycles