Copper-catalyzed conjugate addition of allene-derived nucleophiles to alkenyl-substituted carboxamides

Abstract

Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry. Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging. We herein report a copper-catalyzed conjugate addition of allenes to β-substituted alkenyl amides, one of the most challenging Michael acceptors. The present method utilizes readily available allenes as the latent carbon-based nucleophiles and simple, common β-substituted alkenyl amides as starting materials, unlike previous methods that usually preinstall an activating group to improve the reactivity of amide or uses highly reactive stoichiometric quantities of organometallics. Hence, this approach shows good functional group compatibility and can be implemented under mild reaction conditions with excellent level of chemo- and regioselectivities.