Organocatalytic Activation of Diethyl Glutaconate for the Diastereo- and Enantioselective Assembly of NH-Free 2,3,4-Trisubstituted Pyrrolidines.

Organocatalyzed enantioselective consecutive Michael addition of diethyl glutaconate to a nitro-olefin/reductive cyclization sequence has been developed, directly providing NH-free trans,trans-2,3,4-trisubstituted pyrrolidines with typically >88:12 dr and >90% ee. The obtained structures are closely related to several molecules with high biological profiles, holding great promise for medicinal chemistry. In addition, their potential as direct organocatalysts in the enantioselective Michael addition promoted by enamine activation is also reported.