Base‐Catalyzed Nucleophilic Addition of Oxindoles to 3‐Diazo Oxindoles: An Efficient Approach for the Synthesis of Functionalized Isatin‐Hydrazones

Abstract

AbstractA highly efficient catalytic nucleophilic addition of 3‐substituted oxindoles to 3‐diazo oxindoles has been achieved. This method relies on an organic base catalysis system, which can simultaneously activate 3‐substituted oxindoles as a nucleophile and the diazo compounds as a strong N‐terminal electrophile. Importantly, this approach could yield a broad array of functionalized isatin‐hydrazones featuring an adjacent tetrasubstituted carbon centre of the N(sp3) atom.