A copper-catalyzed tandem reaction for the construction of coumarin fused 9H-pyrrolo[1,2-a]indoles

Abstract

An efficient copper-catalyzed Friedel–Crafts alkylation/cyclization/isomerization sequence of 3-arylcarbonyl coumarins and 3-methyl indole was developed to afford a wide range of functionalized coumarin fused 9H-pyrrolo[1,2-a]indoles, which feature a 6-6-5-5-6 pentacyclic core, in 34–99% yields. Moreover, gram-scale experiment and chemical transformations were conducted to demonstrate the synthetic value of this protocol.