Iron-Mediated Domino Interrupted Iso-Nazarov/Dearomative (3 + 2)-Cycloaddition of Electrophilic Indoles.

An efficient domino reaction combining different classes of pericyclic reactions leads to chiral complex polycyclic indoline-based architectures from achiral starting materials under mild conditions. This practical method is based on the ability of iron(III) chloride to promote both 4π electrocyclizations of 2,4-dienals and the C2-C3 umpolung of N-acetylindoles during the dearomative (3 + 2) cycloadditions.