Asymmetric synthesis of 3-spirocyclopropyl-2-oxindoles via intramolecular trapping of chiral aza-ortho-xylylene

Chiral aza-ortho-xylylene intermediates were efficiently generated from 3-chloro-3-substituted oxindole precursors. The first intramolecular trapping of chiral aza-ortho-xylylene intermediates led to a highly asymmetric synthesis of 3-spirocyclopropyl-2-oxindoles.