Table 2. Base-catalyzed addition of various functional molecules into propiolamide-based scaffolds.
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| Entry a | PA scaffolds b | Thiol c | t [h] | Product | Yield (%) |
| 1 | R1 = c(RGDfK) (2a) | 2-AET-NOTA (Y1) | 1.5 | R2 = 2-AET-NOTA (3a) | 58 |
| 2 | R1 = c(RGDfK) (2a) | 2-AET-Cy5.5 (Y2) | 1.5 | R2 = 2-AET-Cy5.5 (3b) | 60 |
| 3 | R1 = c(RGDfK) (2a) | 2-AET-CH1055 (Y3) | 1.5 | R2 = 2-AET-CH1055 (3c) | 60 |
| 4 | R1 = AE105 (2b) | 2-AET-CH1055 (Y3) | 1.5 | R2 = 2-AET-CH1055 (3d) | 61 |
| 5 | R1 = JMV594 (2c) | 2-AET-CH1055 (Y3) | 1.5 | R2 = 2-AET-CH1055 (3e) | 60 |
| 6 | R1 = AE105 (2b) | 2-AET | 2 | R2 = R3 = 2-AET (4a) | 58 |
| 7 | R1 = c(RGDfK) (2a) | 2-AET-NOTA (Y1), 2-AET-Cy5.5 (Y2) | 2 | R2 = 2-AET-NOTA, R3 = 2AET-Cy5.5 (4b) | 47 |
aThe catalyst DIPEA for entries 1–5; TBD for entries 6–7.
bc(RGDfK) = cyclo (Arg-Gly-Asp-d-Phe-Lys); AE105 = Ac-Lys-Gly-Asp-Cha-Phe-(D)Ser-(D)Arg-Tyr-Leu-Trp-Ser-NH2; JMV594 = (D)Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2.
c2-AET is 2-aminoethanethiol; NOTA is 2-S-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid; Cy5.5 is cyanine 5.5.