Microwave-Assisted Synthesis of 3-Nitroindoles from <i>N</i>-Aryl Enamines via Intramolecular Arene–Alkene Coupling

A variety of N-aryl β-nitroenamines were effectively transformed into 3-nitroindoles in good yields and with complete regioselectivity via a rapid microwave (μW) assisted intramolecular arene-alkene coupling reaction. This report further demonstrates the versatility of this method by constructing 3-carboalkoxy- and 3-cyanoindoles. Optimization data, substrate scope, and applications are discussed.