217. Synthesis of Novel Representatives of Phosphoryl Guanidine Oligonucleotides
Novel representatives of phosphoryl guanidine oligonucleotide derivatives were prepared in this study. A synthetic scheme has been proposed and implemented suitable for the preparation of a wide range of diaminocarbenium azides starting from various secondary amines for subsequent incorporation of tetrasubstituted guanidine residues into the oligonucleotides by the Staudinger reaction. A number of factors which affected the yield of the phosphoryl guanidine derivative were identified, in particular, the size of the alkyl substituents in the azide used, the purity of the azide, and the conditions for elimination of the protecting cyanoethyl group before the final deprotection of the oligonucleotide.