A New Cobalt–Salen Catalyst for Asymmetric Cyclopropanation. Synthesis of the Serotonin–Norepinephrine Repuptake Inhibitor (+)-Synosutine

A new C₂ symmetric cobalt­(II)–salen catalyst based on cis-2,5-diamino­bicyclo­[2.2.2]­octane as the chiral scaffold was prepared which, in the presence of potassium thioacetate as the promoter, catalyzed the formation of cyclopropanes from 1,1-disubstituted ethylenes and ethyl diazoacetate in high yield and with excellent diastereo- and enantioselectivity. Asymmetric cyclopropanation with the catalyst was used in a short, efficient synthesis of the dual serotonin–epinephrine reuptake inhibitor (+)-synosutine.