Visible Light‐Mediated, Acid‐Catalyzed, C−N Cross Dehydrogenative Coupling of Quinoxalin‐2(1<i>H</i>)‐ones with Carbazoles and Amides: Access to Fluorescent Probes Featuring Aggregate Induced Emission
Vikas Dixit, Pooja, Nidhi Jain
Abstract
Abstract We demonstrate a photocatalyst and transition metal catalyst free photo‐activation of quinoxalin‐2(1 H )‐ones in visible light in the presence of an acid catalyst. The photoactivated quinoxalin‐2(1 H )‐one species transfers its energy to oxygen which promotes C−N cross dehydrogenative coupling with nucleophilic partners such as carbazoles, azoles and amides giving the products in 42–75% yields. Preliminary studies reveal quinoxalin‐2(1 H )‐one‐carbazole adducts to display fluorescent properties including Intramolecular Charge Transfer (ICT) and Aggregate Induced Emission (AIE).
Topics & Concepts
ChemistryFluorescencePhotochemistryCatalysisIntramolecular forceAdductCarbazoleVisible spectrumQuenching (fluorescence)Nucleophilic substitutionMedicinal chemistryStereochemistryOrganic chemistryPhysicsOptoelectronicsQuantum mechanicsRadical Photochemical ReactionsCatalytic C–H Functionalization MethodsSynthesis and Biological Evaluation