Fig. 4: Cyclization scope of all l-cyclopeptides.
From: Production of constrained L-cyclo-tetrapeptides by epimerization-resistant direct aminolysis
All yields are HPLC isolation yields. R = Ph, Aliphatic, R1 = H, Me, R2 = Me, Ph, R3 = H, Me. a EDC (2.5 equiv.), HOOBt (2.5 equiv.), CH2Cl2, −10 °C, 1 h. b TFA/TIPSH/H2O = 95/2.5/2.5 (V/V/V), rt, 20 min. c Borax (1.0 equiv.), PBS Buffer, rt, c = 1 mM, pH = 7.4, 4–8 h. d VA-044 (6.0 mM), TCEP (0.07 M), glutathione (0.07 M), 37 °C, 1 h, 2-step one-pot. note: cPYPV (cyclo-Proline-Tyrosine-Proline-Valine), cPLPL (cyclo-Proline-Leucine-Proline-Leucine), cPFPF (cyclo-Proline-Phenylalanine-Proline-Phenylalanine), cPVPV (cyclo-Valine-Proline-Valine).
