Asymmetric Synthesis of Chiral Bicyclic Pyrrolidines via Gold-Mediated Domino Cycloisomerization/(3 + 2)-Annulation Cascades

Herein, we developed an asymmetric catalytic domino cycloisomerization/(3 + 2)-annulation cascade reaction of yne–enones and iminooxindoles using a C1-TunaPhos-gold(I) cationic catalyst, which provided efficient and facile access to highly valuable bicyclic pyrrolidine derivatives in a high yield with excellent enantioselectivity and diastereoselectivity under mild reaction conditions. This synthetic protocol was achieved through the precise (3 + 2)-annulation of in situ generated 1,3-dipole with imines, and its enantioselectivity-determining models are proposed to rationalize the observed stereochemical outcome.