Synthesis of a protected ribonucleoside phosphoramidite-linked spin label via an alkynyl chain at the 5′ position of uridine

Akihiko Hatano, Nanae Terado, Yuichi Kanno, Toshikazu Nakamura, Gota Kawai

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1 Citation (Scopus)


New, spin-labeled nucleosides, and an efficient synthetic route for a modified uridine amidite, were developed. The spin-labeled part was the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) group, which was linked via an alkynyl chain at the 5 position of uridine. Three typical protecting groups, the t-butyldimethylsilyl (TBDMS) group at 2′, the dimethoxytrityl (DMTr) group at 5′, and the phosphoramidite group at 3′, were introduced to produce an automated nucleic acid synthesizer. The TEMPO group at the 5 position in the uridine structure affected introduction of bulky protecting groups, such as the DMTr group at the 5′ position and the TBDMS group at the 2′ position. The electron paramagnetic resonance (EPR) data revealed a nitroxyl radical in the structure of synthetic nucleoside compounds; however, RNA produced by automated synthesis using a TEMPO-linked uridine phosphoramidite building block was EPR silent.

Original languageEnglish
JournalSynthetic Communications
Publication statusAccepted/In press - 2018 Jan 1



  • 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)
  • Electron paramagnetic resonance (EPR)
  • RNA
  • spin label
  • unnatural nucleoside

ASJC Scopus subject areas

  • Organic Chemistry

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