Facile dimer synthesis for DNA-binding polyamide ligands.

Pyrrole-imidazole polyamide ligands are highly sequence specific synthetic DNA-binding ligands that bind with high affinity. To counter the synthetic difficulties associated with coupling the electron-rich heterocyclic acids to the electron-deficient nucleophilic imidazole amine, a novel approach is described for synthesis of Fmoc-protected dimers for solid-phase peptide synthesis (SPPS). This method produces the dimers in high yields, is broadly applicable to other heterocyclic-containing polyamides, and results in improved ligand yields and synthesis times.