A solution-phase phosphoramidite synthesis of short oligonucleotides using solid-supported reagents is described. Polyvinyl pyridinium tosylate is employed as the activator in the coupling step between nucleoside-3'-O-phosphoramidites and 5'-OH nucleosides. The resulting dinucleotide phosphite triesters are oxidized or sulfurized with polymer-bound periodate or tetrathionate to phosphotriesters or thiono phosphotriesters, respectively. Removal of the 3'-O-levulinyl protection is accomplished with a polymer-supported hydrazine. In this approach, the excess reagents are removed by filtration, avoiding complicated purifications. All the polymer-bound reagents used in this method result from salt bridge interactions with the polymers. Consequently, the resins are regenerable.