Synthesis of N-phosphoryl amino acids via phosphoramidite amine-exchange

N-Phosphoryl amino acids were prepared rapidly and in high yield via phosphoramidite amine-exchange in the presence of 1H-tetrazole followed by oxidation with mCPBA. Formation of dibenzyl phosphoramidates incorporating the representative C-terminal protected amino acids leucine, phenylalanine, glutamic acid, and proline were demonstrated to be most successful with dibenzyl N,N-dimethylphosphoramidite although the N,N-diethyl and N,N-diisopropyl analogs also provided high yields. (C) 1998 Elsevier Science Ltd. All rights reserved.