L-α-Amino acids and D-α-amino acids, mediated by phosphorus pentachloride, could take place the phosphorylation and then assembled itno polypeptides. However, β-amino acids could not assemble into polypeptides, and the self-assembly of DL-α-amino acids into peptides were difficult. α-Amino acids could not assemble into peptides mediated by thionyl chloride. The self-assembly reactions were studied by positive ion electrospray ionization mass spectrometry, and the five-membered cyclic penta-coordinated phosphoryl amino acid intermediates were found in the course of self- assembly into peptides. The intermediates could be trapped by ^31P NMR spectroscopy after amino acids were trimethylsilylized to N, O-bis (trimethylsilyl) amino acids.

Key words: PHOSPHORIC CHLORIDE, MASS SPECTROGRAPHY, PHOSPHORUS CHLORIDE, AMINO ACID, POLYPEPTIDE, ORGANO PHOSPHORUS COMPOUNDS, PHOSPHORUS 31 MAGNETIC RESONANCE SPECTROMETRY