Attachment to Nucleobases

Base modification at the 4-position of pyrimidines leads to loss of base-pairing properties. The thiol moiety in 91 was deprotected after ODN synthesis using 1 M DBU in acetonitrile. The modified oligothymidylate was then cleaved from the solid phase and reacted with N-(2-chloroethylthio)phthalimide to yield 92, which was subjected to further derivatization [264]. Purine base positions accessible for ligand attachment are C-8 of adenosine (93) [265] and C-2 of guanosine (94) [266]. 

---

Transition metal ion incorporation in hybrid inorganic-nucleic acid structures adds another dimension to the field of DNA nanotechnology because metal ions, in particular those with unpaired d electrons, have a broad range of electronic and magnetic properties. In most applications in material science, DNA is used as a scaffold for uniform binding of metal ions either to nucleobases or to ligands attached to nucleobases. For example, Braun et al. 

DNA labelled through attachment to nucleobases has been prepared using 4-A(- 6-(y-... 

---