Lewis-acid catalyzed dehydrative [3+2] cycloaddition reaction: A facile synthetic approach to spiro-benzoindoline oxindoles

摘要

An efficient one-pot method for the construction of C-C and C-N bond has been established from activated spiro-aziridine oxindoles using different substituted 2-naphthols by employing BF3 OEt2 as a catalyst. This method features spiro-aziridine ring-opening (Friedel-Crafts type C-C bond formation) with concomitant dehydrative formal [3+2] cycloaddition leading to the formation of a complex and diverse benzoindoline fused spiro-oxindoles in moderate to good yields with wide substrate scope. Moreover, this protocol provides an avenue for the generation of a library of bioactive spiro-cyclic fused heterocyclic motifs which may prove to be of therapeutic interest. (C) 2020 Elsevier Ltd. All rights reserved.