Novel uridin-2′-yl carbamates: synthesis, incorporation into oligodeoxyribonucleotides, and remarkable fluorescence properties of 2′-pyren-1-ylmethylcarbamateElectronic supplementary information (ESI) available: Additional experimental data for compounds 3, 5 and 6. See http://www.rsc.org/suppdata/p1/b1/b111434b/

Abstract

A convenient method for the preparation of uridin-2′-yl carbamate derivatives is described. The stable 2′-O-(imidazol-1-ylcarbonyl)-3′,5′-O-(tetraisopropyldisiloxane-1,3-diyl)uridine, prepared from uridine, was treated with primary or secondary aliphatic amines to give 2′-carbamates in high yield. After 3′,5′-O-deprotection with triethylamine trihydrofluoride, 5′-O-dimethoxytritylation, and 3′-O-phosphitylation with bis(N,N-diisopropylamino)-2-cyanoethoxyphosphine, modified phosphoramidites were obtained and used in machine-assisted synthesis of modified oligodeoxynucleotides containing uridin-2′-yl carbamate residues bearing various N-substituents. The influence of uridin-2′-yl carbamate moieties on the stability of modified oligonucleotide duplexes with complementary DNA and RNA was studied by thermal denaturation experiments. Pyrene-modified oligonucleotides showed a considerable increase in fluorescence intensity upon hybridisation to complementary RNA and interesting binding properties when hybridised to a mismatched DNA.