Total synthesis of a biotinylated derivative of phorboxazole A via sonogashira coupling

The C46 terminus of phorboxazole A has been modified to incorporate a biotin-terminated linker via direct palladium-mediated Sonogashira reaction conditions. Synthetic 45,46-dehydrobromophorboxazole A was joined with a tris-(polyethyleneglycol)vinyl iodide-biotin ester using catalytic PdCl2(PPh3)2, CuI, and Et3N in THF. This process demonstrates the utility of mild carbon-carbon bond formation in the context of phorboxazoles’ architecture and provides a potential affinity probe.