Catalytic Olefin-Imine Metathesis: Cobalt-Enabled Amidine Olefination with Enaminones

Organic metathesis reactions, the transposition/redistribution of molecular fragments between two chemical entities, allow expedient assembly of diverse molecular skeletons and appendages through the merger of whole-piece building blocks. Olefin-imine variant of this chemical process, in particular, can expand the synthetic toolbox for manipulating carbon-carbon and carbon-nitrogen bonds but has thus far been achieved only on a stoichiometric metal-mediated basis. Herein we report the development of a catalytic olefin-imine metathesis reaction, featuring cobalt-catalyzed amidine olefination with enaminones. Comprehensive investigations offer evidence for a mechanistic sequence of exchange of enaminone amine with amidine imine, cobalt-catalyzed cyclization, and ring fragmentation. The reaction provides rapid access to structurally transformed, primary amine-bearing enaminones that can serve as a versatile synthon for further structural diversification.