Scholarship of Discovery
Titanium-catalyzed hydroamination of 1,4- and 1,5-diynes by primary amines leads to imino-alkynes that undergo in situ 5-endo dig and 5-exo dig cyclization reactions, respectively. The products are 1,2,5-trisubstituted pyrroles accessed directly from readily available diyne starting materials.
Ramanathan, Balasubramanian, Adam J. Keith, Douglas Armstrong, and Adam L. Odom. "Pyrrole Syntheses Based on Titanium-Catalyzed Hydroamination of Diynes." Organic Letters 6.17 (2004): 2957-2960.