Simple and stereoselective preparation of an 4-(aminomethyl)-1,2,3-triazolyl nucleoside phosphoramidite

A simple and stereoselective synthesis of a protected 4-(aminomethyl)-1-(2-deoxy-β-D-ribofuranosyl)-1,2,3-triazole cyanoethyl phosphoramidite was developed for the modification of synthetic oligonucleotides. The configuration of the 1,2,3-triazolyl moiety with respect to the deoxyribose was unambiguously determined in ROESY experiments. The aminomethyl group of the triazolyl nucleotide was fully functional in labelling reactions. Furthermore, the hybridization behavior of 5' triazole-terminated oligonucleotide was similar to that of 5' aminohexyl-terminated oligomer with the same sequence. Internal modifications of the oligonucleotide strands resulted in significant decrease of duplex stability.