Chemodivergent Cobalt-Catalyzed Annulation of Aliphatic Amides with Maleimides: (4+1) and (3+2) Pathways for Selective Synthesis

Chemodivergent annulation of aliphatic amides with maleimides has been achieved through either cobalt-catalyzed (4+1) or (3+2) processes. These protocols, utilizing a readily available CoII catalyst, offer a highly efficient method 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 valuable insights into the mechanisms of both processes, elucidating the observed diastereo- and chemoselectivity.