Practical One-Pot Double Functionalizations of Proline

Abstract

Solubilization of proline as the triethylammonium salt allows N-protection (as the Boc, Cbz or Moc derivative) and subsequent esterification or amidation of the carboxy terminus to be performed in an efficient one-pot fashion. Based on this concept, highly practical protocols were developed to prepare a series of proline derivatives (including Pro-Ser dipetides, Weinreb amides and N-protected proline esters), which are important intermediates, for instance, for the synthesis of proline-derived peptides, chiral reagents and catalysts for asymmetric synthesis.