Conditions reported by Albericio and co-workers for the synthesis of the Aib-enkephalin and Aib-ACP peptides on Rink Amide ChemMatrix® and Rink Amide PS resins31.
| Resin | Step | Method 1 (reference) | Method 2 | Method 3 | Method 4 | Method 5 |
|---|---|---|---|---|---|---|
| — | Washing | 1 × DMF | 1 × DMF | 1 × IPA | 1 × EtOAc | 1 × 2-MeTHF |
| 1 × CH2Cl2 | 1 × CH2Cl2 | 3 × EtOAc | ||||
| 1 × DMF | 1 × DMF | 1 × 2-MeTHF | ||||
| — | Deprotection | 20% piperidine in DMF (7 min) | 20% piperidine in DMF (7 min) | 20% piperidine in IPA (7 min) | 20% piperidine in EtOAc (7 min) | 20% piperidine in 2-MeTHF (7 min) |
| — | Washing | 1 × DMF | 1 × DMF | 1 × IPA | 1 × EtOAc | 1 × 2-MeTHF |
| 1 × CH2Cl2 | 1 × CH2Cl2 | 3 × EtOAc | ||||
| 1 × DMF | 1 × DMF | 1 × 2-MeTHF | ||||
| — | Coupling | Fmoc-AA-OH/DIC/Oxyma Pure (3 : 3 : 3 equiv.) 1 h | ||||
| DMF | 2-MeTHF | 2-MeTHF | 2-MeTHF | 2-MeTHF | ||
| Chem-Matrix resin | Purity (%), Aib-enkephalin | 53.0 | 81.9 | 30.8 | 91.9 | 95.0 |
| Purity (%), Aib-ACP | 37.8 | 70.0 | No data | 30.4 | 37.3, 42.8a, 87.1b | |
| PS resin | Purity (%), Aib-enkephalin | 71.8 | 97.0 | No data | 38.6, 54.6a | 41.6, 88.6a |
| Purity (%), Aib-ACP | No data | No data | No data | No data | 7.1a, 25.4b | |
a
Fmoc-removal performed at 40 °C.
b
Fmoc-removal and coupling performed at 40 °C.