Redox-Triggered α‑C–H Functionalization of Pyrrolidines: Synthesis of Unsymmetrically 2,5-Disubstituted Pyrrolidines

By using o-benzoquinone as an internal oxidant, the regio- and diastereoselective functionalization of the secondary over the tertiary α-C–H bond of 2-substituted pyrrolidines is first realized. Subsequent intermolecular addition of a nucleophile to the generated N,O-acetal and cleavage of the aromatic substituent leads to 2,5-disubstituted pyrrolidines.