Pyrrole Syntheses Based on Titanium-Catalyzed Hydroamination of Diynes

Abstract

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-trisubsituted pyrroles accessed directly from readily available diyne starting materials.