Aza‐propargylglycine, azaPra, peptides are branching points for the synthesis of azapeptide libraries. Researchers in the Lubell Lab, published in Peptide Science, found that efficient alkylation of N-(Fmoc)hydrazine in solution provide N'‐propargyl fluorenylmethyl carbazate 13, which on activation gave N-(Fmoc)‐azaPra acid chloride for installation into peptides.

Reducing the number of steps on resin for azaPra peptide synthesis, which previously necessitated alkylation of a semicarbazone protected aza‐glycine residue, the new method offers potential for higher yield, as demonstrated by the synthesis of azacyclopeptide 1a, as well as by an alanine scan of this potent cluster of differentiation‐36 receptor, CD36, modulator. Considering the diverse applications of azaPra residues, the described method offers interesting potential for preparing linear and cyclic azapeptide libraries.

Title:
Aza‐Propargylglycine Installation by Aza‐Amino Acylation: Synthesis and Ala‐Scan of an Azacyclopeptide CD36 Modulator
Authors:
Ahsanullah, Ramesh Chingle, Ragnhild G. Ohm, Pradeep S. Chauhan, William D. Lubell
Citation:
Peptide Science, Volume 111, Issue 1, Special Issue: Emerging Peptide Science in Canada, January 2019
URL:
https://onlinelibrary.wiley.com/doi/abs/10.1002/pep2.24102