Submonomeric strategy with minimal protection for the synthesis of C(2)-modified peptide nucleic acids

Abstract

A novel synthesis of C(2)-modified peptide nucleic acids (PNAs) is proposed, using a submonomeric strategy with minimally protected building blocks, which allowed a reduction in the required synthetic steps. N(3)-unprotected, D-Lys- and D-Arg-based backbones were used to obtain positively charged PNAs with high optical purity, as inferred from chiral GC measurements. “Chiral-box” PNAs targeting the G12D point mutation of the KRAS gene were produced using this method, showing improved sequence selectivity for the mutated- vs wild-type DNA strand with respect to unmodified PNAs.