Application of germyldesulfonylation reactions to the synthesis of germanium-containing nucleoside analogues.
Treatment of the protected (E)-5'-deoxy-5'-[(p-toluenesulfonyl)methylene]uridine and adenosine derivatives with tributyl- or triphenylgermane hydride (AIBN/toluene/Delta) effected radical-mediated germyldesulfonylations to give 5'-(tributyl- or triphenylgermyl)methylene-5'-deoxyuridine and adenosine derivatives as single (E)-isomers. Analogous treatment of 2'-deoxy-2'-[(phenylsulfonyl)methylene]uridine with Ph(3)GeH afforded the corresponding vinyl triphenylgermane product. Stereoselective halodegermylation of the (E)-5'-(tributylgermyl)methylene-5'-deoxy nucleosides with N-iodosuccinimide or N-bromosuccinimide provided the Wittig-type (E)-5'-deoxy-5'-(halomethylene) nucleosides quantitatively, while no halodegermylations was observed with the 5'-deoxy-5'-(triphenylgermyl)methylene counterparts. Treatment of the vinyl trialkylgermanes with aqueous trifluoroacetic acid effected protiodegermylation, while vinyl triarylgermanes were stable under the acidic conditions.
Wnuk
Stanislaw F
SF
Department of Chemistry & Biochemistry, Florida International University, Miami, Florida, USA. wnuk@fiu.edu
Sacasa
Pablo R
PR
Restrepo
Jorge
J
D005857:Germanium / Q000737:chemistry*; D009705:Nucleosides / Q000138:chemical synthesis / Q000737:chemistry*; D013450:Sulfones / Q000138:chemical synthesis / Q000737:chemistry
D009705:Nucleosides; D013450:Sulfones; D005857:Germanium