Directed C–H Alkenylation of Aryl Imines with Alkenyl Phosphates Promoted by a Cobalt–N-Heterocyclic Carbene Catalyst

Abstract

We report herein an ortho-C–H alkenylation reaction of aryl imines with alkenyl phosphates promoted by a cobalt–N-heterocyclic carbene (NHC) catalytic system. While commercially available bulky NHC ligands exhibited only modest catalytic activity, elaboration of the nitrogen substituents and backbone of the NHC enabled the desired transformation to proceed in high yield at a mild temperature. The new Co–NHC system proved applicable to a variety of aryl imines and alkenyl phosphates to afford ortho-alkenylated aryl imines, which serve as precursors to benzofulvene derivatives. (Figure presented.).