4,5-Dicyanoimidazole-promoted synthesis of dinucleoside polyphosphates and their analogs

A general and efficient P(V)-N activation method for the preparation of symmetrical and asymmetrical dinucleoside polyphosphates (NpnN′s, n=2-4) and P2,P3-CX2-dinucleoside tetraphosphates (X=H, F, and Cl) has been established. Twenty-two dinucleoside polyphosphates and their phosphonate analogs were synthesized from nucleoside 5′-phosphoropiperidates with 4,5-dicyanoimidazole as the activator in good to high yields.