Synthesis of Tetrahydroindole Derivatives via Metal-Free Intramolecular [4+2] Annulation of Ynamides
Zhixin Zhang, Tongyi Zhai, Bohan Zhu, Pengcheng Qian, Longwu Ye
Chinese Journal of Organic Chemistry . 2022, (5): 1501 -1508 .  DOI: 10.6023/cjoc202201006