Table 1. Product Distributions Resulting from Oxidation of 2 with a Number of On-Bead Peptide Analogues of 1a,b.
| entry | i | i + 1 | i + 2 | i + 3 | i + 4 | 10,11- (4) | 6,7- (5) | 2,3- (6) |
|---|---|---|---|---|---|---|---|---|
| 1 | Boc-Asp | d-Pro | Thr(Bn) | Asn(Trt) | Tyr(tBu) | 1.2 | 2.3 | 1.0 |
| 2 | Boc-Asp | d-Pro | Thr(Trt) | Asn(Trt) | Tyr(tBu) | 1.1 | 1.5 | 1.0 |
| 3 | Boc-Asp | d-Pro | Ser(Bn) | Asn(Trt) | Tyr(tBu) | 1.1 | 1.7 | 1.0 |
| 4 | Boc-Asp | d-Pro | Ile | Asn(Trt) | Tyr(tBu) | 1.0 | 1.5 | 1.1 |
| 5 | Boc-Asp | d-Pro | Thr(Bn) | Asp(tBu) | Tyr(tBu) | 1.0 | 1.2 | 1.1 |
| 6 | Boc-Asp | d-Pro | Thr(Bn) | Hse(Trt) | Tyr(tBu) | 1.1 | 1.1 | 1.0 |
| 7 | Boc-Asp | d-Pro | Thr(Bn) | Ser(Trt) | Tyr(tBu) | 1.1 | 1.1 | 1.0 |
| 8 | Boc-Asp | d-Pro | Thr(Bn) | Leu | Tyr(tBu) | 1.2 | 1.5 | 1.0 |
| 9 | Boc-Asp | d-Pro | Thr(Bn) | Asn(Trt) | Phe | 1.2 | 2.2 | 1.0 |
| 10 | Boc-Asp | d-Pro | Thr(Bn) | Asn(Trt) | hPhe | 1.2 | 2.1 | 1.0 |
| 11 | Boc-Asp | d-Pro | Thr(Bn) | Asn(Trt) | 2-Nal | 1.2 | 2.3 | 1.0 |
| 12 | Boc-Asp | d-Pro | Thr(Bn) | Asn(Trt) | Cha | 1.2 | 2.2 | 1.0 |
a
Reactions were conducted with 2 (1 μmol, 1.0 equiv), DIC (0.3 equiv), 1-hydroxybenzotriazole (HOBt) (0.1 equiv), 4-dimethylaminopyridine (DMAP) (0.1 equiv), H2O2 (1.0 equiv), dichloromethane (DCM) (0.2 M), and a single bead bound to peptide.
b
2-Nal = 2-naphthylalanine, Cha = cyclohexylalanine, hPhe = homophenylalanine, Hse = homoserine.