Synergistic Catalysis for the Asymmetric [3+2] Cycloaddition of Vinyl Aziridines with α,β‐Unsaturated Aldehydes

The first asymmetric [3+2] cycloaddition of vinyl aziridines with α,β‐unsaturated aldehydes, based on synergistic catalysis, is disclosed. This methodology allows the formation of attractive pyrrolidine structures in good yields (up to 84 %), moderate diastereoselectivity, and high enantioselectivity values (up to >99 % ee ). Additionally, a tricyclic pyrrolidine core structure found in biologically active molecules was synthesized in a one‐pot fashion by using the presented reaction concept. Finally, a mechanistic proposal is outlined.