Divergent C–H Annulation for Multifused N‐Heterocycles: Regio‐ and Stereospecific Cyclizations of N‐Alkynylindoles

This is the authors' abstract. We don't add key points for this paper.

N‐Alkynylindoles were divergently cyclized for the synthesis of multifused N‐heterocycles. An ortho ‐aryl palladium species was added to the α position of an ynamine to generate ( Z )‐6‐alkylidene/benzylidene‐6 H ‐isoindolo[2,1‐ a ]indoles, while Pt‐catalyzed β‐addition through π‐activation gave 5‐alkyl/arylindolo[2,1‐ a ]isoquinolines. Double cyclizations using PdCl 2 and oxidant afforded bright yellow benzo[7,8]indolizino[2,3,4,5‐ ija ]quinolines, the synthesis of which was also demonstrated in a different synthetic route.