Acid-Mediated N–H/α,β-C(sp3)–H Trifunctionalization of Pyrrolidine: Intermolecular [3 + 2] Cycloaddition for the Construction of 2,3-Dihydro‑1H‑Pyrrolizine Derivatives

A one-pot acid-mediated reaction has been developed for the N–H/α,β-C­(sp3)–H trifunctionalization of pyrrolidine without any metallic reagents or external oxidants. This reaction involves the intermolecular [3 + 2] cycloaddition of in situ-generated azomethine ylides with acrylic esters to provide facile access to 2,3-dihydro-1H-pyrrolizine derivatives in high yields under mild conditions.