Enantioselective Amino Acid Synthesis by Chiral Phase-Transfer Catalysis

The alpha-amino acids, which are usually formulated as H2NCH(R)CO2H despite their zwitterionic nature, are by far the most important, numerous, and diverse family of the naturally occurring amino acids. Although a set of only 19 together with the heterocyclic amino acid proline comprises the building blocks from which polypetide chains are assembled under genetic control, the total number of alpha-amino acids identified as occurring free of incorporated in natural product of animals, plants and microorganisms is estimated in the hundreds, and the list of such alpha-amino acids grows all the time.