Electrophilic Cyclization of Aryl Propargylic Alcohols: Synthesis of Dihalogenated 6,9-Dihydropyrido[1,2‑a]indoles via a Cascade Iodocyclization

A strategy for the synthesis of 6,9-dihydropyrido­[1,2-a]­indoles through a cascade iodocyclization of 4-(3-methyl-1H-indol-1-yl)-1,1-diphenylbut-2-yn-1-ol derivatives is presented. This reaction was conducted under very mild conditions and in a short time. The reactions are metal-free, are environmentally friendly and give up to 94% yield. Moreover, the obtained halides allow functional group diversification by palladium-catalyzed coupling reactions, which could act as potential intermediates for the synthesis of valuable compounds.