Construction of meta-Disubstituted Triaryls via Iodine-Catalyzed Oxidative Aromatization Coupling of Cycloalkenes with Indoles

Abstract

meta-Disubstituted triaryls are privileged scaffolds in bioactive molecules and functional materials, but their efficient synthesis remains challenging, due to limitations in regioselectivity and reliance on prefunctionalized substrates or transition metals. Herein, an iodine-catalyzed oxidative aromatization strategy is reported for the construction of meta-triaryls via direct coupling of readily available cycloalkenes with indoles. This protocol enables regioselective CC bond formation at the indole C3-position and a subsequent dehydrogenative desaturation of the cycloalkene component to form the meta-substituted arene motif. The method features broad substrate scope, accommodating diverse substituted cycloalkenes and indoles. Key advantages include economical catalyst (HI as iodine source), avoidance of precious metals, and operational simplicity. Additionally, the products can undergo an array of synthetic transformations, including heterocycle skeleton editing to quinolines, halogenations, and photoredox functionalizations, which highlight the potential applications of this strategy.