Regio- and Enantioselective Synthesis of Pyrrolidines Bearing a Quaternary Center by Palladium-Catalyzed Asymmetric [3 + 2] Cycloaddition of Trimethylenemethanes

Herein we describe the first use of disubstituted donors
in the
palladium-catalyzed trimethylenemethane (TMM) cycloaddition resulting
in an enantioselective synthesis of highly substituted pyrrolidines.
These cyanoalkyl donors 1 form all-carbon quaternary
centers in a catalytic, asymmetric, and intermolecular manner uniquely
using diamidophosphite ligands L2 and L3, generating synthetically important chiral building blocks in good
yields and selectivities.