EFFICIENT SYNTHESIS OF 6-SUBSTITUTED PURINE DERIVATIVES USING Pd-CATALYZED CROSS-COUPLING REACTIONS WITH 2'-DEOXYGUANOSINE O6-TOSYLATE

摘要

6-Substituted purine analogs function in a variety of biological activities including antiviral pathways.A number of studies have reported on the development of the efficient synthesis of these nucleoside analogs.We previously demonstrated that oligonucleotides containing 2-amino-6-vinylpurine derivatives react with the cytosine at the target site with extreme selectivity.This was the first finding that O6-tosylate derivative of guanosine worked as an efficient substrate for Pd(0)-catalyzed cross-coupling reaction with vinyltributylstannane to produce 2-amino-6-vinylpurine.In order to demonstrate usefulness of the tosylate precursor,in this study we investigated transition metal catalysts and ligands in achieving the cross-coupling reaction using boronic acids or Grignard reagents as a coupling partner.