Copper-catalyzed dearomative 1,4-carboxylate rearrangement of 2-carbonateindoles

A novel dearomative 1,4-rearrangement reaction of 2-carbonateindoles with aryl diazoacetates has been developed in the presence of a copper catalyst, which might proceed through a tandem formation of a zwitterionic intermediate, intramolecular cyclization and ring-opening reaction to give the final rearrangement products containing an all-carbon quaternary center with two newly formed C-C bonds. In this sequence, the disruption of the aromaticity of indole has been realized, associated with 1,4-carboxylate rearrangements.