Reagents and conditions: (a)
4-iodoaniline, EDC, DCM, rt, 4 h, 88%; (b) Ph3 Bi, Cu(OAc)2, TEA, DCM, overnight, rt, 48%; (c) (i) TFA/DCM (1:1), 0.5 h, rt;
(ii) Fmoc-Tle-OH, EDC, TEA, DCM, 6 h, 78%; (d) 20% piperidine/DMF,
47%; (e) 3, NMM, DMAP (cat), DMF, rt 2 h, 66%.