Synthesis of orthogonally protected vicinal diamines with amino acid-based skeleton

A convenient route to amino acid-based orthogonally protected 1,2-diamines starting from materials readily available for a peptide chemist is presented. The key step of the procedure is the Mitsunobu reaction of N-protected aminoalcohol, obtained by the reduction of commercially available Z- or Boc-protected amino acid, with imidodicarbonate or sulfonylcarbamate related to standard amino-protecting groups used in peptide chemistry yielding triprotected vicinal diamines.