UNIT 1.25 Synthesis of the Tellurium-Derivatized Phosphoramidites and Their Incorporation into DNA Oligonucleotides

In this unit, an efficient method for the synthesis of 2¢-tellerium-modified phosphoramidite and its incorporation into oligonucleotide are presented. We choose 5¢-O-DMTr-2,2¢-anhydro-uridine and -thymidine nucleosides (S.1, S.2) as starting materials due to their easy preparation. The 5¢-O-DMTr-2,2¢-anhydro-uridine and -thymidine can be converted to the corresponding 2¢-tellerium-derivatized nucleosides by treating with the telluride nucleophiles. Subsequently, the 2¢-Te-nucleosides can be transformed into 3¢-phosphoramidites, which are the building blocks for DNA/RNA synthesis. The DNA synthesis, purification, and applications of oligonucleotides containing 2¢-Te-U or 2¢-Te-T are described in the protocol. Curr. Protoc. Nucleic Acid Chem. 47:1.25.1-1.25.16. © 2011 by John Wiley & Sons, Inc.

Keywords: tellurium nucleic acid; nucleic acid modification; Te-derivatized DNA; nucleic acid X-ray crystallography; DNA damaging; conductive DNA; DNA imaging