A diastereoselective three-component coupling approach to highly substituted pyrrolidines.

Building on the observation that metal complexation facilitates azomethine ylide formation, we report that chelating aldehydes participate in metal-templated, one-pot reactions with unprotected amino acid esters and activated olefins to provide highly substituted pyrrolidines. The high yields, broad substrate scope, excellent diastereoselectivities, functional group tolerance, and incorporation of commercially available materials in this reaction simplifies access to medicinally relevant proline derivatives.