Copper(I)-Catalyzed Cycloisomerization of 1H-Indole N-Tethered o-Alkynylnitroarenes to C2-Spiropseudoindoxyl Compounds

A protocol for the efficient and expeditious synthesis of the pentacyclic C2-spiropseudoindoxyl scaffold that relies on a copper(I)-catalyzed 6-endo-dig cycloaddition/internal redox (IR)/anthranil formation/oxaziridine formation/ring-opening spirocyclization/reduction cascade of 1H-indole N-tethered o-alkynylnitroarenes is described.