Template-Directed Synthesis of Oligoguanylic Acids- Metal Ion Catalysis

Abstract

The condensation of guanosine 5′-phosphorimidazolide on a poly(C) template is subject to regiospecific metal-ion catalysis. In the presence of the Pb²⁺ ion, predominantly [2′–5′]- linked oligomers up to the 40-mer are formed. The Zn²⁺ ion catalyzes the formation of predominantly [3′–5′]-linked oligomers up to the 35-mer. The Sn²⁺, Sb³⁺ and Bi³⁺ ions also catalyze the formation of [2′–5′]-linked products, but less efficiently than the Pb²⁺ ion.