Figure 1.
Synthesis of bicyclic peptide library. Reagents and Conditions: (a) Standard Fmoc/HATU chemistry; (b) soak in water; (c) 0.4 equiv Fmoc-OSu in Et2O/CH2Cl2; (d) di-t-butyl dicarbonate; (e) piperidine; (f) 4-hydroxybenzoic acid/HBTU/HOBT; (g) Fmoc-β-Ala-OH/DIC; (h) 50% TFA in DCM; (i) split-and-pool synthesis by Fmoc/HATU chemistry; (j) 2% TFA in DCM (6x); (k) Fmoc-OSu/ DIPEA in DCM; (l) Pd(PPh3)4; (m) diallyl protected trimesic acid/HATU; (n) PyBOP/HOBT/DIPEA; (o) modified reagent K.