Abstract
Oligdeoxynucleotides containing phosphoramidote internucleotide links 3'-OP(O)NH-5' have been prepared using standard solid phase phosphoramidite techniques. For the incorporation of the phosphoramkkrte linkages we have used monomer as well as dimer building blocks. With die monomer 3'-phosphoramidite building blocks, which are derived from 5'-amino-2', 5'-dideoxynucleosides, it is possible to incorporate phosphoramidate links into specific positions widiin an oligodeoxynucleotide. Furthermore the synthesis of several dinucleoside phosphate derivatives which are linked by phosphoramidate bonds are described. The internucleotide phosphoramidate linkage was performed using die Staudinger reaction followed by a Michaelis-Arbuzov type transformation. After 3'-phosphitylation these dinucleosides are compatible with the current phosphoramidite methodology of oligodeoxynucleotide synthesis.