Cobalt-catalyzed C–H annulation of aliphatic amides with maleimides: chemodivergent (4 + 1) and (3 + 2) pathways

Abstract

Chemodivergent C–H annulation of aliphatic amides with maleimides has been achieved under cobalt-catalysis, enabling access to distinct (4 + 1) and (3 + 2) outcomes. These protocols, utilizing a readily available Co^II-catalyst, deliver a powerful strategy for the synthesis of a diverse range of spiro-γ-lactams (spiropyrrolidin-2-ones) and bicyclic pyrrolidin-2,5-diones. The combination of DFT and experimental studies provides mechanistic insight into both processes, revealing the origins of their diastereo- and chemoselectivity.