Zinc promoted rapid and efficient synthesis of Fmoc-and Z-#alpha,#alpha#-dialkylamino acids under neutral conditions

摘要

The introduction of N~#alpha##-9-fluorenylmethyloxycarbonyl(Fmoc) and benzyloxycarbonyl(Z) groups into #alpha#,#alpha#-dialkylamino acids is described at neutral pH using Fmoc-Cl or Z-Cl as an acylating agent respectively in the presence of activated zinc powder.The reaction is simple,fast and clean.It also perimits the scale up with high yields.It is completely free from protected oligomer formation,which is a known side-reaction when Schotten-Baumann procedure is followed.All the Fmoc-and Z-amino acids prepared have been fully characterized.