A diastereoselective synthetic route to tetrahydrocyclopenta[c]pyrrole-1,3-dione derivatives via Cu(I)-catalyzed desymmetrization of maleimide with N-sulfonyl cyclopropylamines.

Herein, we report a Cu(I)-catalysed desymmetrization of maleimide with cyclopropylamines to access tetrahydrocyclopenta[c]pyrrole-1,3-dione derivatives in high yields (up to 86%) with excellent diastereoselectivities (up to dr > 99 : 1) under mild reaction conditions. The reaction pathway involves the generation of a carbon centered radical from the opening of the cyclopropane ring, followed by intermolecular Michael type addition to maleimide, and finally 5-exo-trig radical cyclisation. Tetrahydrocyclopenta[c]pyrrole-1,3-dione scaffolds are present in several natural products and are of pharmaceutical importance.