N-Iminopyridinium ylide-directed, cobalt-catalysed coupling of sp2 C–H bonds with alkynes

Abstract

N-Iminopyridinium ylides are competent monodentate directing groups for cobalt-catalysed annulation of sp² C–H bonds with internal alkynes. The pyridine moiety in the ylide serves as an internal oxidant and is cleaved during the reaction. The annulation reactions possess excellent compatibility with heterocyclic substrates, tolerating furan, thiophene, pyridine, pyrrole, pyrazole, and indole functionalities.