Highly Efficient Synthesis of DNA-Binding Hairpin Polyamides via the Use of a New Triphosgene Coupling Strategy

A facile and highly efficient solid phase synthesis method is reported for the preparation of hairpin DNA-binding polyamides using the cost-effective triphosgene (BTC) activating agent. Difficult polyamide sequences were prepared from N-methylimidazole (Im) and N-methylpyrrole (Py) building blocks with high stepwise yields (>98%) using Boc chemistry. The versatility of the triphosgene coupling approach was also demonstrated for the first time on aryl hydrazine resins to afford biomedically relevant tail-truncated polyamides in excellent isolated yields.