Dialkylphosphoryl amino acids

An intramolecular phosphoric-carboxylic mixed anhydride has been proposed to explain the specific behavior of AT-(dialkylphosphoryl)amino acids 15 that spontaneously give oligopeptides upon standing in various solvents [115]. Peptide formation was accompanied by diester exchange on the phosphoryl group via a reaction that may have been useful for nucleotide ligation. 

The possibilities of N-(dialkylphosphoryl)amino acids for the prebiotic syntheses of peptides and polynucleotides have been studied in a series of papers [24,116-122], However, it must be emphasized that the phosphoryl group does not behave as an amino-activating group, the hydrolysis of which would be coupled to peptide bond formation. Actually, further peptide elongation requires the subsequent hydrolysis of the N-terminal phosphoryl group of the ligated product. In the presence of an amino acid ester, dipeptide esters 16 with an unreacted N-phosphoryl protection are formed, support-... 

In relation with the unique reactivity of N-(dialkylphosphoryl)amino acids mentioned above (see Sect. 3.2.3), a conversion of the carboxylic-phosphoric mixed anhydride 18f (R1 = R2 = alkyl) would provide an appealing pathway for the formation of the AT-phosphorylated derivatives. The reaction of NCAs might have then allowed a pathway for the formation of these versatile intermediates that can be useful for nucleotide ligation. 

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See also in sourсe #XX -- [ ]

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