A mild route to indoles by cyclization of 2-(1-alkynyl)anilines is offered by the use of simple bases such as KOtBu, KH, or CsOtBu and N-methylpyrrolidinone (NMP) at room temperature. The reaction has a broad scope and allows the preparation of various functionalized indoles as well as new aza-or diazaindoles in excellent yields [see, for example, Eq. (1)].
Angewandte Chemie - International Edition
2488 - 2490