Selective diphosphorylation, dithiodiphosphorylation, triphosphorylation, and trithiotriphosphorylation of unprotected carbohydrates and nucleosides

[GRAPHIC] Aminomethyl polystyrene resin-bound linkers of p-acetoxybenzyl alcohol were subjected to reactions with diphosphitylarting and triphosphitylating reagents to yield the corresponding polymer-bound cliphosphitylating and triphosphitylating reagents, respectively. A number of unprotected carbohydrates and nucleosides were reacted with the polymer-bound reagents. Oxidation with tert-butyl hydroperoxide or sulfurization with Beaucage's reagent, followed by removal of cyanoethoxy group with DBU and the acidic cleavage, respectively, afforded only one type of monosubstituted nucleoside and carbohydrate diphosphates, dithiodi phosphates, triphosphates, and trithiotriphosphates with high regioselectivity.