Pyridine‐N‐Oxide as a Mild Reoxidant Which Transforms Osmium‐Catalyzed Oxidative Cyclization

The PNOman can: The use of pyridine-N-oxide (PNO) transforms the catalytic oxidative cyclization to include the formation of pyrrolidines from N-Z-protected amino alcohols and amino acids (see scheme; Z=PhCH2OCO). This new method expands the scope of the oxidative cyclization as illustrated with the synthesis of a range of di- and trisubstituted pyrrolidines with complete control of stereochemistry.