Expanding the Chemical Space of Non‐Proteinogenic N4‐Substituted Asparagine: Racemic, Enantioenriched, and Deuterated Derivatives

A site‐selective carbamoylation strategy to access non‐proteinogenic N4‐modified asparagines has been described. The protocol is characterized by mild reaction conditions, high functional group compatibility, and a wide diversity of functionalized carbamoyl radicals making possible the access to peptides, pharmaceuticals, and natural N4‐asparagine conjugates, as well as enantioenriched unnatural N4‐asparagines. Besides that, deuterated analogues were achieved with the insertion of D2O and enantioenriched derivatives could be obtained in 15 min in continuous‐flow conditions. A site‐selective carbamoylation strategy to access non‐proteinogenic N4‐modified asparagines is reported. The protocol is characterized by mild reaction conditions, high functional group compatibility, and a wide diversity of functionalized carbamoyl radicals. The protocol was further extended to access a large chemical space of N4‐asparagine conjugates (racemic, enantioenriched and deuterated).