Asymmetric (5 + 3) Annulation of Donor–Acceptor Cyclopropanes with Imidazolidines: Access to Saturated 1,4-Diazocanes

Saturated 1,4-diazocanes are highly important for medicinal chemistry and drug discovery, but their syntheses are often tedious. Herein, we report a copper-catalyzed (5 + 3) annulation of donor–acceptor cyclopropanes with imidazolidines, thereby providing a straightforward method to access a library of saturated 1,4-diazocanes in moderate to excellent yields under mild reaction conditions. More importantly, the asymmetric version of this (5 + 3) annulation leading to optically active saturated 1,4-diazocanes is achieved by two strategies: (i) chirality transfer and (ii) dynamic kinetic asymmetric transformation by employing copper triflate with an SaBOX ligand. In addition, the analogous (6 + 3) annulation of donor–acceptor cyclopropanes with hexahydropyrimidines is also realized.