Metal-Free C-H Amination for Indole Synthesis
Young Ho Jang and So Won Youn*
*Center for New Directions in Organic Synthesis, Department of Chemistry and Research Institute for Natural Sciences, Hanyang University, Seoul 133-791, Korea, Email: sowony73hanyang.ac.kr
Y. H. Jang, S. W. Youn, Org. Lett., 2014, 16, 3720-3723.
DOI: 10.1021/ol5015398 (free Supporting Information)
The use of DDQ as an oxidant enables an effective metal-free C-H amination of N-Ts-2-alkenylanilines to afford a diverse range of substituted indoles. This operationally simple and robust protocol obviates the need of expensive transition-metal catalysts, and offers a broad substrate scope. A mechanism involving a radical cation generated by SET and a migratorial process via a phenonium ion intermediate is proposed.
see article for more examples