Site-selective direct arylation of unprotected adenine nucleosides mediated by palladium and copper: insights into the reaction mechanism

Thomas E. Storr, Andrew G. Firth, Karen Wilson, Kate Darley, Christoph G. Baumann, Ian J.S. Fairlamb

Research output: Contribution to journalArticle

Abstract

Reaction conditions facilitating the site-selective direct aryl functionalisation at the C-8 position of adenine nucleosides have been identified. Many different aromatic components may be effectively cross-coupled to provide a diverse array of arylated adenine nucleoside products without the need for ribose or adenine protecting groups. The optimal palladium catalyst loading lies between 0.5 and 5 mol %. Addition of excess mercury to the reaction had a negligible affect on catalysis, suggesting the involvement of a homogeneous catalytic species. A study by transmission electron microscopy (TEM) shows that metal containing nanoparticles, ca. 3 nm with good uniformity, are formed during the latter stages of the reaction. Stabilised PVP palladium colloids (PVP=N-polyvinylpyrrolidone) are catalytically active in the direct arylation process, releasing homogenous palladium into solution. The effect of various substituted 2-pyridine ligand additives has been investigated. A mechanism for the site-selective arylation of adenosine is proposed.
Original languageEnglish
Pages (from-to)6125-6137
Number of pages13
JournalTetrahedron
Volume64
Issue number26
Early online date18 Jan 2008
DOIs
Publication statusPublished - 23 Jun 2008

Fingerprint

Palladium
Adenine
Nucleosides
Copper
Metal Nanoparticles
Povidone
Ribose
Colloids
Catalysis
Transmission Electron Microscopy
Mercury
Adenosine
Metals
Nanoparticles
Ligands
Transmission electron microscopy
Catalysts

Keywords

  • direct arylation
  • purines
  • C–C Bond formation
  • palladium
  • copper(I) salts

Cite this

Storr, Thomas E. ; Firth, Andrew G. ; Wilson, Karen ; Darley, Kate ; Baumann, Christoph G. ; Fairlamb, Ian J.S. / Site-selective direct arylation of unprotected adenine nucleosides mediated by palladium and copper : insights into the reaction mechanism. In: Tetrahedron . 2008 ; Vol. 64, No. 26. pp. 6125-6137.
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Site-selective direct arylation of unprotected adenine nucleosides mediated by palladium and copper : insights into the reaction mechanism. / Storr, Thomas E.; Firth, Andrew G.; Wilson, Karen; Darley, Kate; Baumann, Christoph G.; Fairlamb, Ian J.S.

In: Tetrahedron , Vol. 64, No. 26, 23.06.2008, p. 6125-6137.

Research output: Contribution to journalArticle

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