Table 1.

Solid-phase synthesis strategies for the azole-based peptidomimetics.

No	Intermediate Resin	Cyclized Product	Key Strategies
1			1. Formation of key intermediate 78 from resin-bound dipeptide, aldehyde, and benzotriazole; 2. Cyclization achieved via BF3∙Et2O treatment [49].
2			1. Formation of thiourea intermediate 80 at the N-terminal of the peptide; 2. Dehydrothiolation of 80 via Mukaiyama’s reagent [50].
3			1. Incorporation of secondary amino acid into the peptide sequence; 2. Cyclization via HgCl2, or DIC, or Mukaiyama’s reagent [51].
4			1. Oxidation and dehydrative cyclization of the Thr, Cys, Ser, diaminopropionic acid-containing dipeptides [52].
5			1. Backbone amide linker (BAL) strategy; 2. Thiosemicarbazide resin coupled with an amino acid to give thiourea intermediate 86; 3. Desulfurative cyclization of 86 with p-TsCl and pyridine; 4. Incorporation of 3-nitrobenzoyl functionality [53].
6			1. BAL strategy; 2. N-Bn-protected thiourea resin intermediate 88 was used to prevent undesired byproduct; 3. Dehydrative cyclization of 88 with 2-bromo-(3-nitrophenyl)ethenone [54].
7			1. Traceless linker strategy; 2. Cyclization of 90 with ethyl bromoacetate to yield 1,3-thiazole [55].
8			1. Cyclization of 92 with hydrazides in the presence of Hg(Ac)2 [56].
9			1. One-pot Ugi-azide-4CR strategy [57].