Oxidative (3 + 2) Cycloaddition Reactions of Diaza-Oxyallyl Cationic Intermediates and Indoles for the Synthesis of Imidazoloindolines

An oxidative diaza-(3 + 2) cycloaddition reaction of simple urea derivatives with substituted indoles has been developed. This transformation provides rapid access to highly functionalized imidazoloindolines that are represented in bioactive compounds. The reported method is compatible with a wide variety of functional groups and directly provides unique heterocyclic scaffolds from indoles and a simple urea derivative.