Complex Hydroindoles by an Intramolecular Nitrile-Intercepted Allylic Alkylation Cascade Reaction

Bisnucleophilic reagents derived from malononitrile, ketones, benzaldehydes, and nitromethane can react with bisallylic electrophiles via a nitrile-intercepted allylic alkylation cascade reaction to yield complex hydroindole architectures. Also noteworthy is that the only stoichiometric byproducts from the preparation and reaction of the bisnucleophile and biselectrophile are water, acetic acid, and bicarbonate, making it a potentially “green” platform for multistep complex molecule synthesis. These scaffolds can be converted into hydrooxindoles by a unique olefin isomerization followed by Witkop–Winterfeldt-like oxidation.