SYNTHESIS OF 5-SUBSTITUTED-URACIL PNA MONOMERS BY Pd-CATALYZED CROSS-COUPLINGS

摘要

Peptide nucleic acids (PNAs), containing N-(2-aminoethyl)glycine backbone instead of sugar-phosphate moiety of the natural nucleic acids, belong to the most powerful and promising DNA mimics due to their strong hybridization ability with DNA and RNA and complete resistance to nucleases and proteases. In oligonucleotides 5-C-substitution of uracil base, among other things, makes possible the introduction of fluorophores and spin labels. In addition, PNA-DNA chimeras as well as normal DNA oligomers containing 5-propynyl-uracils in place of thymines have higher duplex stability and increased mismatch recognizing ability. Incorporation of different 5-heteroaryl-uracil moieties into short oligodeoxynucleotides also results in enhanced thermal stability of the modified DNA:RNA duplexes compared to that of the thymine-containing counterpart.