Reversal of Enantioselectivity between the Copper(I)- and Silver(I)-Catalyzed 1,3-Dipolar Cycloaddition Reactions Using a Brucine-Derived Amino Alcohol Ligand

The old switcheroo: The switch in the enantioselectivity of a reaction by using a single chiral source has been achieved using different metal binding modes of the chiral amino alcohol 1 in the presence of CuI and AgI sources. Azomethine ylides were shown to undergo highly enantio‐ and diastereoselective 1,3‐dipolar cycloadditions with substituted tert‐butyl acrylates to provide both of the enantiomerically enriched pyrrolidines (see scheme).