A Unified Approach to Access N-Acyl Sulfonamide Tethered Peptide Conjugates

Herein we demonstrate a chemoselective reaction of N-beta-protected amino alkyl sulfonyl azides with in situ generated N-alpha-protected amino acid selenocarboxylates via step wise intramolecular cyclization followed by decomposition to obtain N-acyl sulfonamide tethered peptidyl conjugates. The protocol offers the synthesis of orthogonally protected N-acyl sulfonamide tethered peptidomimetics under simple and mild reaction conditions employing commercially available amino acids in presence of NaBH2Se3 as a selenating agent. Also, the synthesis of N-acyl sulfonamide tethered amino acid and aryl conjugates were accomplished as an extension of the above strategy.